Delay documentation deployment

This should hopefully fix any possible issues where the NPM package
may be released after the documentation is deployed, which could cause
a cause miss by jsDelivr and cause the documentation to cache without
pulling in the Select2 dependency.

It hasn't happened yet, but I'm concerned it could happen and I don't
want to put in the effort to make a more sophisticated way of
handling this issue.

Author: kevin-brown

.github/workflows/docs-deploy.yml

@@ -7,6 +7,9 @@ jobs:
     name: Deploy Grav
     runs-on: ubuntu-latest
     steps:
+      - uses: maddox/actions/sleep@master
+        with:
+          args: "60"
       - uses: actions/checkout@v1
       - name: Copy to documentation server
         uses: maxheld83/rsync@v0.1.0