Remove extra newlines around components in Markdown

[hippotastic]

Changes

• Fixes 🐛 BUG: Using HTML inside markdown produces additional space. #3493.
• Removes the extra newlines that the previous code wrapped around mdxJsxFlowElement and mdxJsxTextElement elements with children in Markdown. These extra newlines caused unwanted whitespace to be introduced into the resulting HTML output.

Testing

• Updated test cases to reflect the new correct output.
• Ran all tests locally.
• Built Astro Docs using the new code without apparent issues.

Docs

• Just a bugfix.

[changeset-bot]

🦋 Changeset detected

Latest commit: 3a9887d

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
astro	Patch
@astrojs/markdown-remark	Patch

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[hippotastic]

@natemoo-re PTAL :) The failed Windows test should be a fluke.

[natemoo-re]

LGTM, thanks as always!

[ahmed2m]

I think this bug (or a variation of it) is present now in .astro files?
https://replit.com/@ahmed2m/Astro-spacing-problem#src/pages/index.astro

[hippotastic]

@ahmed2m I don't think that this is a bug. In my opinion, what you're seeing here is regular HTML whitespace handling which doesn't have anything to do with Astro. Your code will lead to the same results without even using Astro, but only plain HTML.

Newlines, tabs and spaces are all considered whitespace characters in HTML, and all whitespace characters will be collapsed to one single space (not zero!) by the browser when displaying the page. If you do not want to introduce whitespace into the output, but still wrap lines in your code, you can do something like this:

    <h2>
      Instead, you can add whitespace before the closing bracket of the
      <span class="test">span</span
      >, which works well!
    </h2>

See an example here:
https://stackblitz.com/edit/web-platform-hqtn6w?file=index.html

Hope that helps! :)

[ahmed2m]

Yeah, I was using JSX for the longest time and it collapses new lines/spaces into nothing that I thought that's like an html thing.

My problem is I use the prettier plugin and somehow it ALWAYS formats like jsx, (usually) break lines around tags