Markdown: turn plain URLs into links

[danyx23]

By default, plain link like https://domain.com are not shown as links in markdown (see commonmark spec) and instead have to be written in the [text](https://domain.com) style.

This PR adds autolinking to plain links. This is done in two different way

• once for the SimpleMarkdown component that uses react-remark via a remark transformation plugin
• and once for the MarkdownTextWrap component by doing the translation as part of the mapping to IRNodes

In theory it should be possible to use the remark plugin in both cases, but navigating the set of interdependent libraries at the state two years ago is a pain and so I went for the two bespoke versions. When we upgrade our setup to be ESM everywhere we can upgrade to the latest versions of the unified, react-remark et al libraries and try again to use the same code in both cases.

[danyx23]

Current dependencies on/for this PR:

• master
  • PR ✨ add react-remark library, test it in SimpleMarkdownText #2875
    • PR ✨ Switch all markdown rendering to react-remark #2872
      • PR Markdown: turn plain URLs into links #2884 👈
        • PR Markdown: special handling of DoD links #2873
          • PR 🔨 fix minor rebase issues #2874

This stack of pull requests is managed by Graphite.

[marcelgerber]

Ah, now that I think of it, including .?: can be annoying in cases like Learn more at https://ourworldindata.com/poverty..

I know that some other sites do something like "match .?: unless they are at the very end of the URL", which seems sensible.

[danyx23]

Good catch. I took this opportunity to also make sure we match urls with unicode word characters in the path.

AFAIK to properly match this with a regex you need to use negative lookbehind assertions and they are not supported in Safari before 16.4 which came out in Spring this year so I instead handle trailing punctuation characters in the replacement function.

[danyx23]

Merge activity

• Nov 7, 3:55 PM: @danyx23 started a stack merge that includes this pull request via Graphite.
• Nov 7, 3:56 PM: Graphite couldn't merge this pull request because a downstack PR ✨ add react-remark library, test it in SimpleMarkdownText #2875 failed to merge.
• Nov 7, 4:03 PM: @danyx23 started a stack merge that includes this pull request via Graphite.
• Nov 7, 4:03 PM: @danyx23 merged this pull request with Graphite.