workflow: add build and markdown_lint

[gitveg]

添加build和markdown_lint。
本地仓库已测试，均可以正常运行。

[inscripoem]

Node.js is not a dependence of mkdocs. There is no need to setup node.

[inscripoem]

These are settings regarding to GitHub Pages, which belongs to the deployment. You may remove these lines without consequences.

[inscripoem]

For the linting workflow, these is not a comprehensible log in the test run, showing an execution line and an exiting line.

More importantly, considering the site contains mostly Chinese content, we need a linting tool specifically built for this scenario. Try zhlint with the modified configuration from our club.

Please kindly take https://github.com/hust-open-atom-club/hust-mirrors/blob/master/.github/workflows/lint.yaml as reference.

Btw, I will recommend including a test run link (or more, if needed) with every workflow in the PR description.

[inscripoem]

Meanwhile, due to the logic of all the changes to the main branch should be made by PR, I think the trigger should be limited to PRs on main branch. You can check the discussion on Feishu.