explicitly installing nodejs

.github/workflows/main.yml

@@ -2,7 +2,7 @@ name: Build docs
 
 on:
   # Specify to run a workflow manually from the Actions tab on GitHub.
-  workflow_dispatch:
+  workflow_dispatch: ""
 
 # Gives the workflow permissions to clone the repo and create a page deployment
 permissions:
@@ -31,7 +31,9 @@ jobs:
       - name: Prepare for build
         run: |
           apt-get update
-          apt-get install -y zip
+          apt-get install -y zip curl
+          curl -fsSL https://deb.nodesource.com/setup_20.x | sudo -E bash -
+          apt-get install -y nodejs
           mkdir -p artifacts
       - name: Build docs # and include sitemap.xml TODO: uncomment when sitemap.xml is available
         run: |