Add commenting from github-actions bot (#5)

.github/workflows/preview.yml

@@ -28,15 +28,16 @@ jobs:
         run: |
           output=$(fern generate --docs --preview)
           echo "$output"
-          # Extract the URL and append it to GITHUB_ENV
-          echo "preview_url=$(echo "$output" | grep -oP '(?<=Published docs to )https://[^\s]*')" >> $GITHUB_ENV
-          
+          # Extract the URL
+          preview_url=$(echo "$output" | grep -oP '(?<=Published docs to )https://[^\s]*')
+          # Set the output for the step
+          echo "::set-output name=preview_url::$preview_url"
       - name: Comment PR with URL using github-actions bot
         uses: actions/github-script@v4
         if: ${{ steps.generate_docs.outputs.preview_url }}
         with:
           script: |
-            const preview_url = '${{ env.preview_url }}';
+            const preview_url = '${{ steps.generate_docs.outputs.preview_url }}';
             const issue_number = context.issue.number;
             github.issues.createComment({
               ...context.repo,