Rectify Functions roles (#1676)

* Rectify Functions roles

Enablement team pointed out that Functions roles are available to all tiers, not just BT so have made some modifications here to reflect this. Open to any copy changes as suggested by the docs team - please feel free to go ahead with those before approving/merging. Thanks!

* Apply suggestions from code review

Co-authored-by: LRubin <[email protected]>

Author: Andy

src/segment-app/iam/roles.md

@@ -17,6 +17,12 @@ Members inherit custom permissions based on [individual roles](#business-tier-ro
 - **Source admin**
   Source admins have edit access to assigned source(s), to the settings for that source, to any connected streaming destinations, schema, and live data from the source in the [debugger](/docs/connections/sources/debugger/). A user with the Source Admin role can be granted access to either all current and future Sources, or a specific list of Sources, or (if you are on a Business plan) to Sources with a specific Label.
 
+- **Functions Admin**
+Functions admins can create, edit and delete access to assigned function(s). When you assign a user the Functions Admin role, you can grant them access to either _all current and future_ functions, or to a _specific list_ of functions.
+
+- **Functions Read-only**
+The Functions read-only role grants users the ability to read an assigned function(s). When you assign a user the Functions Read-only role, you can grant them access to either _all current and future_ functions, or to a _specific list_ of functions.
+  
 
 ## Business Tier Roles
 
@@ -46,18 +52,6 @@ Read access to all warehouses and warehouse settings.
 
 **Scope:** Grants access to **all** warehouses.
 
-#### Functions Admin
-
-Create, edit and delete access to assigned function(s).
-
-**Scope:** Can be granted access to either all current and future functions, or to a specific list of functions.
-
-#### Functions Read-only
-
-Read access to assigned function(s).
-
-**Scope:** Can be granted access to either all current and future functions, or to a specific list of functions.
-
 #### Tracking Plan Admin
 
 Edit access to all Tracking Plans in Protocols.