add Orb destination documentation

Author: Thomas Gilbert

src/connections/destinations/catalog/orb/index.md

@@ -0,0 +1,40 @@
+---
+title: Orb Destination
+id: 625ed45387dd6603f5380424
+---
+[Orb](https://www.withorb.com/) provides scalable, reliable, and flexible billing infrastructure for usage based revenue models at companies of all sizes.
+
+This destination is maintained by Orb. For any issues with the destination, [Contact the Orb support team](mailto:[email protected]).
+
+## Getting Started
+
+{% include content/connection-modes.md %}
+
+1. From the Destinations catalog page in the Segment App, click **Add Destination**.
+2. Search for "Orb" in the Destinations Catalog, and select the "Orb" destination.
+3. Choose which Source should send data to the "Orb" destination.
+4. Go to the [Orb dashboard](https://app.billwithorb.com), create a new API key from the configuration's page or reuse an existing one. We recommend creating a new API key for this integration.
+5. Enter the "API Key" in the "Orb" destination settings in Segment.
+6. Fill out the settings for properties' mapping fields, external customer Id, Idempotency key (optional), and event name (optional).
+
+## Supported methods
+
+Orb currently supports track calls, as specified in the [Segment Spec](/docs/connections/spec).
+
+### Track
+
+Use [Track](/docs/connections/spec/track) calls to automatically send usage events based on your customer's interactions with your application. Any Segment track call will be ingested through [Orb's ingestion pipeline](https://docs.withorb.com/docs/orb-docs/event-ingestion) and usage information will be used to calculate billable totals. For example:
+```js
+analytics.track({
+  event: "payment_confirmed",
+  userId: "external_customer_id",
+  properties: {
+    amount: 100.00,
+    currency: "USD",
+    confirmation_time: "2022-05-11T21:33:13.1652304793Z"
+  }
+});
+```
+Similar to Segment, Orb supports a flexible event schema in the `properties` dictionary, which should be non-null and not contain nested objects. Within Orb, you can configure metrics by filtering and aggregating events. When you configure the Orb destination, you will be required to specify a mapping of keys from the original Segment event to Orb’s usage event. You’ll also be able to configure keys corresponding to Orb’s required fields such as `event_name` , `idempotency_key`, and `external_customer_id`. 
+
+Events ingested via the track spec will be available on the Orb admin dashboard, specifically on the [Events page](https://app.billwithorb.com/events).