Updating GitHub Action for GitHub Pages build

Author: cchesser

.github/workflows/gh-pages.yml

@@ -7,20 +7,20 @@ on:
 
 jobs:
   deploy:
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     defaults:
       run:
         working-directory: ./docs
     steps:
       - uses: actions/checkout@v2
         with:
-          submodules: recursive  # Fetch the Docsy theme
-          fetch-depth: 0         # Fetch all history for .GitInfo and .Lastmod
+          submodules: true
+          fetch-depth: 0
 
       - name: Setup Hugo
         uses: peaceiris/actions-hugo@v2
         with:
-          hugo-version: '0.96.0'
+          hugo-version: '0.120.4'
           extended: true
 
       - name: Setup Node