Prepare docs for release 22.1.0 (GH-2826)

Author: ichard26

Diff for: CHANGES.md

@@ -1,6 +1,6 @@
 # Change Log
 
-## Unreleased
+## 22.1.0
 
 At long last, _Black_ is no longer a beta product! This is the first non-beta release
 and the first release covered by our new stability policy.

Diff for: docs/integrations/source_version_control.md

@@ -7,7 +7,7 @@ Use [pre-commit](https://pre-commit.com/). Once you
 ```yaml
 repos:
   - repo: https://github.com/psf/black
-    rev: 21.12b0
+    rev: 22.1.0
     hooks:
       - id: black
         # It is recommended to specify the latest version of Python

Diff for: docs/usage_and_configuration/the_basics.md

@@ -173,7 +173,7 @@ You can check the version of _Black_ you have installed using the `--version` fl
 
 ```console
 $ black --version
-black, version 21.12b0
+black, version 22.1.0
 ```
 
 An option to require a specific version to be running is also provided.