feat(billing): Updated invoice terms to receipts and bills (#15374)

## DESCRIBE YOUR PR
We are moving away from the term "invoice", so updated docs to reflect
the latest terminology: bill/billing and receipt.

Preview: 
-
https://sentry-docs-git-billing-term-updates.sentry.dev/pricing/quotas/manage-seer-budget/
-  https://sentry-docs-git-billing-term-updates.sentry.dev/pricing/
-
https://sentry-docs-git-billing-term-updates.sentry.dev/pricing/legacy-pricing/

## IS YOUR CHANGE URGENT?  

Help us prioritize incoming PRs by letting us know when the change needs
to go live.
- [x] Urgent deadline (GA date, etc.): Ideally today
- [ ] Other deadline: <!-- ENTER DATE HERE -->
- [ ] None: Not urgent, can wait up to 1 week+

## SLA

- Teamwork makes the dream work, so please add a reviewer to your PRs.
- Please give the docs team up to 1 week to review your PR unless you've
added an urgent due date to it.
Thanks in advance for your help!

## PRE-MERGE CHECKLIST

*Make sure you've checked the following before merging your changes:*

- [ ] Checked Vercel preview for correctness, including links
- [ ] PR was reviewed and approved by any necessary SMEs (subject matter
experts)
- [ ] PR was reviewed and approved by a member of the [Sentry docs
team](https://github.com/orgs/getsentry/teams/docs)

Co-authored-by: Shannon Anahata <shannonanahata@gmail.com>

Author: sfanahata

docs/pricing/index.mdx

@@ -175,18 +175,18 @@ Issue Fixes are billed per run. Interactions with the same run will only be bill
 
 <Alert>
   Billing or Owner-level users have the permissions to make changes to
-  information on the Subscription page and access invoices. If you need an
-  invoice, but don't have the right permissions, reach out to your
+  information on the Subscription page and access receipts. If you need a
+  receipt, but don't have the right permissions, reach out to your
   administrator.
 </Alert>
 
 Your billing cycle will be either monthly or annually, depending on the contract term of your subscription, and whether or not you are using pay-as-you-go (PAYG):
 
-- **Annual Subscriptions:** You will be invoiced annually at the beginning of your billing cycle for your paid plan and reserved volume. If you use PAYG, you will receive a monthly invoice for this usage.
+- **Annual Subscriptions:** You will be billed annually at the beginning of your billing cycle for your paid plan and reserved volume. If you use PAYG, you will receive a monthly bill for this usage.
 
-- **Monthly Subscriptions:** You will be invoiced monthly at the beginning of your billing cycle for your paid plan and reserved volume. If you use PAYG, the invoice you receive will also include any PAYG usage from the previous billing cycle.
+- **Monthly Subscriptions:** You will be billed monthly at the beginning of your billing cycle for your paid plan and reserved volume. If you use PAYG, the bill you receive will also include any PAYG usage from the previous billing cycle.
 
-Users with [Billing or Owner-level](/organization/membership/) permissions can find their invoices by going to the [**Settings**](https://sentry.io/orgredirect/organizations/:orgslug/settings/) page and clicking “Subscription” (under the “Usage & Billing” heading.)
+Users with [Billing or Owner-level](/organization/membership/) permissions can find their receipts by going to the [**Settings**](https://sentry.io/orgredirect/organizations/:orgslug/settings/) page and clicking "Subscription" (under the "Usage & Billing" heading.)
 
 ### Changing Plans Mid-cycle
 
@@ -299,7 +299,7 @@ However, in some countries, both B2C and B2B customers need to be charged sales
 
 ### Tax Exemptions
 
-If your company or non-profit organization qualifies for a sales tax exemption, you can reach out to tax@sentry.io with the following information to have sales tax removed from any future invoices:
+If your company or non-profit organization qualifies for a sales tax exemption, you can reach out to tax@sentry.io with the following information to have sales tax removed from any future bills:
 
 - Organization name
 - Copy of a signed tax exempt certificate
@@ -309,4 +309,4 @@ If you've submitted an exemption form, and you're still being charged sales taxe
 - The exemption certificate was still in review after the billing period was closed.
 - The exemption certificate covers a state that is different from your billing address.
 
-Updating your address or submitting a tax exemption certificate doesn't impact the taxes charged on older invoices. We do not adjust the billing or invoicing of a closed billing period.
+Updating your address or submitting a tax exemption certificate doesn't impact the taxes charged on older bills. We do not adjust the billing of a closed billing period.

docs/pricing/legacy-pricing.mdx

@@ -234,8 +234,8 @@ In most cases, new budgets will take effect within minutes. Otherwise, we guaran
 
 <Alert>
   You have to have Billing or Owner-level permissions to make changes to
-  information on the Subscription page or access invoices. If you need an
-  invoice, but don't have the right permissions, reach out to your
+  information on the Subscription page or access receipts. If you need a
+  receipt, but don't have the right permissions, reach out to your
   administrator.
 </Alert>
 
@@ -245,7 +245,7 @@ Sentry uses two different billing cycles: one for your paid plan and reserved vo
 - **On-demand cycle** - Billing cycle for your on-demand volume. On-demand charges are calculated in a one-month window and billed on a monthly basis.
 
 _If you're on a monthly subscription billing cycle, your on-demand billing cycle will be aligned to it._
-Users with [Billing or Owner-level](/organization/membership/) permissions can find their invoices by going to the [**Settings**](https://sentry.io/orgredirect/organizations/:orgslug/settings/) page and clicking "Subscription" (under the "Usage & Billing" heading.)
+Users with [Billing or Owner-level](/organization/membership/) permissions can find their receipts by going to the [**Settings**](https://sentry.io/orgredirect/organizations/:orgslug/settings/) page and clicking "Subscription" (under the "Usage & Billing" heading.)
 
 ## Plans & Free Trials
 
@@ -345,7 +345,7 @@ However, in some countries, both B2C and B2B customers need to be charged sales
 
 ### Tax Exemptions
 
-If your company or non-profit organization qualifies for a sales tax exemption, you can reach out to tax@sentry.io with the following information to have sales tax removed from any future invoices:
+If your company or non-profit organization qualifies for a sales tax exemption, you can reach out to tax@sentry.io with the following information to have sales tax removed from any future bills:
 
 - Organization name
 - Copy of a signed tax exempt certificate
@@ -355,4 +355,4 @@ If you've submitted an exemption form, and you're still being charged sales taxe
 - The exemption certificate was still in review after the billing period was closed.
 - The exemption certificate covers a state that is different from your billing address.
 
-Updating your address or submitting a tax exemption certificate doesn't impact the taxes charged on older invoices. We do not adjust the billing or invoicing of a closed billing period.
+Updating your address or submitting a tax exemption certificate doesn't impact the taxes charged on older bills. We do not adjust the billing of a closed billing period.

docs/pricing/quotas/manage-seer-budget.mdx

@@ -89,7 +89,7 @@ Let's illustrate how this works:
    - Your issue fix automation is set to "Highly Actionable and Above".
    - Of the 1,000 issues scanned, 50 are identified as "Highly Actionable and Above". As soon as the issue is classified, Seer automatically creates RCAs and suggested fixes for these 50 issues so that they are immediately available for your review.
    - The total issue fix cost is $50.
-4. **Seer Invoice:**
+4. **Seer Bill:**
 
    - Total Seer usage: $3 (scans) + $50 (fixes) = $53.
    - $25 is covered by your monthly Seer Credit.