Move vale vocab main to dir that vale >=3.0.0 expects (#4385)

Co-authored-by: Naomi Pentrel <[email protected]>

Author: adit-chandra

.github/vale/styles/Vocab/main/accept.txt renamed to .github/vale/styles/config/vocabularies/main/accept.txt

@@ -29,7 +29,7 @@ jobs:
           source env/bin/activate
       - uses: errata-ai/vale-action@reviewdog
         with:
-          version: 2.30.0
+          version: 3.12.0
           reporter: github-check
           filter_mode: file
           fail_on_error: true