Give render-samples runner write permission (#61)

Author: chrisfenner

.github/workflows/docker-publish.yml

@@ -88,7 +88,7 @@ jobs:
     container:
       image: ghcr.io/trustedcomputinggroup/pandoc_test
     permissions:
-      contents: read
+      contents: write
 
     steps:
       - name: Checkout repository
@@ -116,4 +116,4 @@ jobs:
         with:
           commit_message: Generate latest PDF
           file_pattern: guide.pdf
-        if: github.event_name != 'pull_request'
+        if: github.event_name != 'pull_request'