Generate docs made friendly for PRs from forks

Only publish sources and comments with link to them for PRs
opened from branches in this repo. PRs from forks would have
artifacts with rendered docs uploaded.

Author: oleksandr-pavlyk

.github/workflows/generate-docs.yml

@@ -76,7 +76,7 @@ jobs:
           mv ../cmake-install/docs/docs ~/docs
           git clean -dfx
       - name: Publish docs
-        if: ${{ github.ref == 'refs/heads/master' }}
+        if: ${{ ! github.event.pull_request.head.repo.fork && github.ref == 'refs/heads/master' }}
         shell: bash -l {0}
         run: |
           git remote add tokened_docs https://IntelPython:${{ secrets.GITHUB_TOKEN }}@github.com/IntelPython/dpctl.git
@@ -91,8 +91,15 @@ jobs:
           git config --global user.email 'github-actions[doc-deploy-bot]@users.noreply.github.com'
           git commit -m "Latest docs."
           git push tokened_docs gh-pages
+      - name: Save built docs as an artifact
+        if: ${{ ! github.event.pull_request.head.repo.fork && github.event.pull_request && github.event.action != 'closed'}}
+        uses: actions/upload-artifact@v3
+        with:
+          name: ${{ env.PACKAGE_NAME }} rendered documentation
+          path: ~/docs
+
       - name: Publish pull-request docs
-        if: ${{ github.event.pull_request && github.event.action != 'closed' }}
+        if: ${{ ! github.event.pull_request.head.repo.fork && github.event.pull_request && github.event.action != 'closed' }}
         env:
           PR_NUM: ${{ github.event.number }}
         shell: bash -l {0}
@@ -111,7 +118,7 @@ jobs:
           git commit -m "Docs for pull request ${PR_NUM}"
           git push tokened_docs gh-pages
       - name: Unpublish pull-request docs
-        if: ${{ github.event.pull_request && github.event.action == 'closed' }}
+        if: ${{ ! github.event.pull_request.head.repo.fork && github.event.pull_request && github.event.action == 'closed' }}
         env:
           PR_NUM: ${{ github.event.number }}
         shell: bash -l {0}
@@ -128,7 +135,7 @@ jobs:
           git commit -m "Removing docs for closed pull request ${PR_NUM}"
           git push tokened_docs gh-pages
       - name: Comment with URL to published pull-request docs
-        if: ${{ github.event.pull_request && github.event.action != 'closed' }}
+        if: ${{ ! github.event.pull_request.head.repo.fork && github.event.pull_request && github.event.action != 'closed' }}
         env:
           PR_NUM: ${{ github.event.number }}
         uses: mshick/add-pr-comment@v1