README: API-Version: Official support for Jira Cloud API in version 3

Author: andygrunwald

CHANGELOG.md

@@ -343,6 +343,7 @@ client.Project.GetAll(ctx, &GetQueryOptions{})
 
 * UserAgent: Client HTTP calls are now identifable via a User Agent. This user agent can be configured (default: `go-jira/2.0.0`)
 * The underlying used HTTP client for API calls can be retrieved via `client.Client()`
+* API-Version: Official support for Jira Cloud API in [version 3](https://developer.atlassian.com/cloud/jira/platform/rest/v3/intro/)
 
 ### Bug Fixes
 

README.md

@@ -331,9 +331,11 @@ We follow the [Atlassian Support End of Life Policy](https://confluence.atlassia
 
 #### Jira Cloud
 
-* Jira Cloud API in [version 2](https://developer.atlassian.com/cloud/jira/platform/rest/v2/intro/)
+We support Jira Cloud API in [version 3](https://developer.atlassian.com/cloud/jira/platform/rest/v3/intro/).
+Even if this API version is _currently_ in beta (by Atlassian):
 
-Jira Cloud API in [version 3](https://developer.atlassian.com/cloud/jira/platform/rest/v3/intro/) is _currently_ not officially supported, because it is still in beta.
+[Version 2](https://developer.atlassian.com/cloud/jira/platform/rest/v2/) and version 3 of the API offer the same collection of operations.
+However, version 3 provides support for the [Atlassian Document Format (ADF)](https://developer.atlassian.com/cloud/jira/platform/apis/document/structure/) in a subset of the API.
 
 ### Official Jira API documentation