Allow building docs from main (#53)

We eventually only want to support building docs from release branches
and tags, however, while we're working to initially set up the docs, we
may have some churn. So we want to be able to publish from main during
that churn.

Signed-off-by: Kathryn Baldauf <k_baldauf@apple.com>

.github/workflows/docs-release.yaml

@@ -7,7 +7,7 @@ on:
 jobs: 
   checkBranch:
     runs-on: ubuntu-latest
-    if: startsWith(github.ref, 'refs/tags') || startsWith(github.ref, 'refs/heads/release')
+    if: github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/tags') || startsWith(github.ref, 'refs/heads/release')
     steps:
       - name: Branch validation 
         run: echo "Branch ${{ github.ref_name }} is allowed"