chore: commit populate-readme only when chagnes

Sometimes action is started because some data.js only some style changes
And on generate working tree is empty
And action fails because nothing to commit

.github/workflows/populate-readme.yml

@@ -40,7 +40,10 @@ jobs:
         git add readme.md
         git config --local user.email "action@github.com"
         git config --local user.name "GitHub Action"
+        # commit only if any changes
+        if [ ! -z "$(git status --porcelain)" ]; then
         git commit -m "chore: generate \`readme.md\`, lint \`src/data.js\`"
+        fi
 
     - name: Push changes
       uses: ad-m/github-push-action@master