update docs_build.yaml

update docs_build.yaml

Pull Request resolved: https://github.com/ydb-platform/ydb/pull/443

.github/workflows/docs_build.yaml

@@ -14,5 +14,5 @@ jobs:
       - name: Build
         uses: diplodoc-platform/docs-build-action@v3
         with:
-          revision: "pr-${{ github.event.pull_request.number }}"
-          src-root: ${{ vars.SRC_ROOT }}
+          revision: "pr-${{ github.event.pull_request.number }}-${{ github.event.pull_request.head.sha }}"
+          src-root: "./ydb/docs"