build: Validate XML (#71)

.github/workflows/check.yml

@@ -12,3 +12,8 @@ jobs:
         uses: ludeeus/action-shellcheck@master
         env:
           SHELLCHECK_OPTS: -x --source-path=src -e SC1091 -e SC2001 -e SC2034 -e SC2064 -e SC2317 -e SC2153
+      - name: Validate XML
+        uses: anyone-developer/anyone-validate-xml@main
+        with:
+         file-extension: '.xml'
+         read-path: 'assets'