fix: code block in jsx should be ignored

[JounQin]

Partially fix #207

Code blocks in jsx should always be ignored, but I don't know if it is good to drop them in AST, or is there any better way?

Additionally, <details><summary >Override element states</summary> is parsed as a single jsx node from remark-mdx, it could not be handled correctly at https://github.com/mdx-js/eslint-mdx/blob/master/packages/eslint-mdx/src/traverse.ts#L41 which expects <details> and <summary >Override element states</summary> separately, is that possible to do it in remark-mdx? @wooorm

The temporary workaround is:

<details>

<summary >Override element states</summary>

</details>

What means that depends on user to make sure that <details> is a single jsx node.

[codecov-commenter]

Codecov Report

Merging #208 into master will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            master      #208   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           19        19           
  Lines          411       411           
  Branches        76        77    +1     
=========================================
  Hits           411       411           

Impacted Files	Coverage Δ
packages/eslint-mdx/src/traverse.ts	100.00% <100.00%> (ø)

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[wooorm]

What makes you think that this is related to code blocks?

Anyway: this is a limitation of MDX 1. And solved in MDX 2.

[JounQin]

<details>

<summary >Override element states</summary>

```jsx
import Foo from './foo'

export const Bar = () => <Foo />
``` // 

</details>

I mean even if I separate <detail> jsx node, the inner code block will cause parsing error for now.

Because they are wrapped into a jsx node at https://github.com/mdx-js/eslint-mdx/blob/master/packages/eslint-mdx/src/traverse.ts#L24:

const jsxNode = {
  type: 'jsx',
  value: `<details>

<summary >Override element states</summary>

\`\`\`jsx
import Foo from './foo'

export const Bar = () => <Foo />
\`\`\`

</details>`
}

I don't find a good way to preserve the code block into ESLint AST without modifying its value.

[JounQin]

It's a bad fix, we need to find a better way to handle markdown content inside jsx for ESLint.