fix autolabeler by adding permissions and pull requests events

[shenxianpeng]

Right now we have supported autolabeler https://github.com/cpp-linter/.github/blob/b7268d7afd1af602b91a4d494478bcd56f4f8e72/.github/release-drafter.yml#L75-L88

but it doesn't work actually. from the docs https://github.com/toolmantim/release-drafter we need to

• [x] add permission to https://github.com/cpp-linter/.github/commit/b7268d7afd1af602b91a4d494478bcd56f4f8e72
• [x] add pull request events to workflow. e.g.: https://github.com/cpp-linter/cpp-linter-hooks/pull/41

[2bndy5]

Also add rst files for Sphinx docs

     files: 
       - '*.md' 
       - '*.rst'