Add Vale PR check back in (#1492)

Author: devalog

.github/workflows/vale.yml

@@ -0,0 +1,37 @@
+name: Vale style check
+on: 
+  pull_request:
+    paths:
+      - '**.mdx'
+      - '**.md'
+      - '.vale/**'
+      - '.vale.ini'
+      - '!**/changelog/**'
+
+jobs:
+  vale:
+    runs-on: ubuntu-latest
+    if: |
+      github.event.pull_request.user.login != 'fern-support' &&
+      github.event.pull_request.user.login != 'github-actions'
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Get changed files
+        id: changed-files
+        uses: tj-actions/changed-files@v41
+        with:
+          files: |
+            fern/**/*.md
+            fern/**/*.mdx
+          files_ignore: |
+            **/changelog/**
+      - uses: errata-ai/vale-action@reviewdog
+        if: steps.changed-files.outputs.any_changed == 'true'
+        with:
+          files: ${{ steps.changed-files.outputs.all_changed_files }}
+          version: 3.12.0
+          reporter: github-pr-review
+          fail_on_error: false
+        env:
+          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}

.vale.ini

@@ -23,6 +23,7 @@ Microsoft.Spacing = NO
 Microsoft.Semicolon = NO # Mostly just picks up code
 Microsoft.SentenceLength = NO # Mostly just picks up code
 Microsoft.Dashes = NO
+Microsoft.Foreign = NO
 
 # Not relevant for Fern audience
 Microsoft.GeneralURL = NO