Run demo GitHub Action in parallel (#2484)

* Run demo GitHub Action in parallel

* Fix path of action yml

* Move checkout to demo action

* Prettier format

* Specifying shell

* Try to fix uses

* Fix spelling issue

* Fix demo

* Downloading artifacts too unreliable

Building instead

* Re-name step

Re-use action elsewhere

.github/actions/validate-docx/action.yml

@@ -0,0 +1,14 @@
+name: Extract and Validate Document ⚙️
+description: Extract the document and validate the XML against the schema.
+
+runs:
+    using: composite
+    steps:
+        - name: Extract Word Document
+          shell: bash
+          run: npm run extract
+        - name: Validate XML
+          uses: ChristophWurst/xmllint-action@v1
+          with:
+              xml-file: build/extracted-doc/word/document.xml
+              xml-schema-file: ooxml-schemas/microsoft/wml-2010.xsd