Fix title to "Microsoft Writing Style Guide" (#1946)

- Minor grammar fix

Author: stevepiercy

docs/contributing/documentation/authors.md

@@ -332,7 +332,7 @@ Although Plone 6 Documentation is not completely aligned with the Diátaxis fram
 
 ## Plone documentation styleguide
 
-We follow [Microsoft Writing Style Guide](https://learn.microsoft.com/en-us/style-guide/welcome/).
+We follow the [Microsoft Writing Style Guide](https://learn.microsoft.com/en-us/style-guide/welcome/).
 
 Key concepts from that guide include the following.
 

docs/contributing/documentation/setup-build.md

@@ -138,7 +138,7 @@ Open `/_build/linkcheck/output.txt` for the entire list of links that were check
 
 ### `vale`
 
-`vale` checks for American English spelling, grammar, syntax, and the Microsoft Developer Style Guide.
+`vale` checks for American English spelling, grammar, and syntax, and follows the Microsoft Writing Style Guide.
 See {ref}`authors-english-label` for configuration.
 
 ```shell