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/styles/Vocab/Base/accept.txt

@@ -0,0 +1,4 @@
+(?i)Medusa
+(?i)Qovery
+(?i)Netlify
+(?i)s3