Switch to a cleaner theme. (#8)

* Switch to a cleaner theme.

* Add icons and images where appropriate.

azure-pipelines-pr-gate.yml

@@ -13,7 +13,7 @@ steps:
     versionSpec: '3.7'
     architecture: 'x64'
 
-- script: python -m pip install --upgrade pip mkdocs mkdocs-macros-plugin
+- script: python -m pip install --upgrade pip mkdocs mkdocs-macros-plugin mkdocs-material
   displayName: 'Install tools'
 
 - task: CmdLine@1

mkdocs.yml

@@ -1,12 +1,16 @@
 site_name: Project Mu
 repo_url: https://github.com/microsoft/mu
 copyright: Copyright (c) Microsoft.  All rights reserved
-theme: readthedocs
 site_description: "Project Mu Documentation"
 plugins:
     - search
     - macros
 
+theme:
+  name: 'material'
+  custom_dir: 'theme'
+  logo: 'img/mu.png'
+
 nav:
   - Home: 'index.md'
   - FAQ: 'faq.md'