feat: replace remark-cli with eslint-plugin-mdx

[JounQin]

Motivation: remark-lint is great, and we have been using ESLint with it together, but it is redundant to lint .mdx twice by two separate tools, so I added support for linting markdown syntax by remark plugins of course inside eslint-plugin-mdx.

What means we can reduce devDependencies and simplify linting usage as my PR changes.

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related: @rxts/eslint-plugin-mdx has been renamed to eslint-plugin-mdx, thanks to @azz

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[JounQin]

@johno Would you like to review this PR or give some feedback?

[wooorm]

Hey @JounQin, people typically explain why they are creating a PR. In fact, we have a template for that, but you didn’t use it.

Could you give us info on what this does and why it should land?

[JounQin]

@wooorm Sorry I ignored the comment, I will finish that part soon later.

[JounQin]

@wooorm Please review the PR description again.

[silvenon]

⭐️

[wooorm]

Alright, looks good!

[johno]

Thanks @JounQin!