docs: integrate Vale for documentation linting (#2242)

* added value rules

* resolved errors raised by vale

* added github action

* fixes to github action

* added details in contribution guidelines

* added rule for numbers

* limited checks to errors

docs/content/usage.md

@@ -1,5 +1,7 @@
 # Collected Usage Information
 
+<!-- vale docs.We = NO -->
+
 This document gives an overview of Medusa’s optional collected usage information, how it helps Medusa become a better platform, and how developers can opt out of this feature.
 
 ## Overview
@@ -48,3 +50,5 @@ Or, you can run the following command in the root of your Medusa server project
 ```bash
 medusa telemetry --disable
 ```
+
+<!-- vale docs.We = YES -->