workflows: add a check to update cli commands docs when changes occur

Signed-off-by: Andrey Butusov <andrey@nspcc.io>

.github/workflows/cli-docs-update.yml

@@ -15,19 +15,9 @@ jobs:
         with:
           fetch-depth: 0
 
-      - name: Save current CLI docs files
-        run: |
-          mkdir -p backup_docs
-          cp -r docs/cli-commands/* backup_docs/
-
       - name: Generate new CLI doc files
         run: make cli-gendoc
 
-      - name: Compare CLI docs files
+      - name: Check for documentation changes
         run: |
-          DIFF_OUTPUT=$(diff -ur docs/cli-commands backup_docs || true)
-          if [ -n "$DIFF_OUTPUT" ]; then
-            echo "CLI documentation has not been updated correctly. Differences:"
-            echo "$DIFF_OUTPUT"
-            exit 1
-          fi
+          git diff --exit-code -- docs/cli-commands/ || (echo "CLI documentation has not been updated correctly. Differences:" && git diff -- docs/cli-commands/)