Form Recognizer v3.1 GA (2023-07-31) (Azure#24634)

* Copy 2023-02-28-preview to 2023-07-31

* v3.1 GA changes

* Update documentation for REST docs

Author: bojunehsu

specification/cognitiveservices/data-plane/FormRecognizer/readme.md

@@ -4,17 +4,24 @@
 
 Configuration for generating Form Recognizer SDK.
 
-The current release is `2022-08-31`.
+The current release is `2023-07-31`.
 
 ``` yaml
 
-tag: 2022-08-31
+tag: 2023-07-31
 add-credentials: true
 openapi-type: data-plane
 ```
 
 # Releases
 
+### Release 2023-07-31
+These settings apply only when `--tag=2023-07-31` is specified on the command line.
+``` yaml $(tag) == '2023-07-31'
+input-file:
+  - stable/2023-07-31/FormRecognizer.json
+```  
+
 ### Release 2023-02-28-preview
 These settings apply only when `--tag=2023-02-28-preview` is specified on the command line.
 ``` yaml $(tag) == '2023-02-28-preview'