Create new "Good first issue" issues for the community

[mjang]

As we set up this repository for the open source community, potential contributors may ask "What can I do to help." I'd like to create some "Good First Issue" issues, suitable for:

• Community members who want to improve our documentation
• Developers who've tried our content
• Technical Writers

Ideally, these issues would create more 'value' for the documentation. Example: docs verification issues such as those described in pingcap/docs#15480

To help with the process, we have:

• A style guide (based primarily on the Microsoft Manual of Style)
• Instructions for building documentation locally, in https://github.com/nginx/documentation/blob/main/CONTRIBUTING_DOCS.md