updated workflow to exclude markdown files (#2358)

Author: MaikuB

Diff for: .github/workflows/validate.yml

@@ -2,9 +2,13 @@ name: validate
 
 on:
   pull_request:
+    paths-ignore:
+      - '**.md'
   push:
     branches:
       - master
+    paths-ignore:
+      - '**.md'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}