Add mkdocs-macros-plugin

Add `mkdocs-macros-plugin` to resolve deploy error related to Error: MkDocs encountered an error parsing the configuration file: while constructing a Python object `cannot find module 'materialx.emoji' (No module named 'material')` in GitHub Pages.

requirements.txt

@@ -3,6 +3,7 @@ cairosvg
 jinja2>=3.0.2
 markdown>=3.2
 mkdocs>=1.4.0
+mkdocs-macros-plugin>=1.0.4
 mkdocs-material-extensions>=1.0.3
 mkdocs-minify-plugin
 #mkdocs-multirepo-plugin