mkdocs: add page (#8759)

pages/common/mkdocs.md

@@ -0,0 +1,20 @@
+# mkdocs
+
+> Project documentation with Markdown.
+> More information: <https://www.mkdocs.org>.
+
+- Create a new mkdocs project:
+
+`mkdocs new {{project_name}}`
+
+- Serve the project in the current directory using the mkdocs dev-server:
+
+`mkdocs serve`
+
+- Build the documentation in the current directory:
+
+`mkdocs build`
+
+- Deploy the documentation in the current directory to GitHub pages:
+
+`mkdocs gh-deploy`