README.org uses Markdown link syntax for the YouTube video link

[kiwigitops]

Problem

README.org mixes Markdown link syntax into an Org-mode file. Around line 17:

You can find detailed documentation of the library and how to use
it in [[https://github.com/janestreet/incremental/blob/master/src/incremental_intf.ml][incremental/src/incremental_intf.ml]].  You can also find an
informal introduction to the library in this [[https://blog.janestreet.com/introducing-incremental][blog post]]
and [this video](https://www.youtube.com/watch?v=G6a5G5i4gQU).

The other two links use correct Org syntax ([[url][description]]), but [this video](https://www.youtube.com/watch?v=G6a5G5i4gQU) is Markdown syntax. GitHub renders .org files with org-ruby, which does not interpret Markdown link syntax, so this renders as the literal text [this video](https://www.youtube.com/watch?v=G6a5G5i4gQU) and is not clickable on github.com/janestreet/incremental.

This was introduced in #16 ("Readme to link to video.", merged 2024-05-06), which used Markdown syntax even though the file extension is .org.

Expected

The video link should be clickable on the rendered README, just like the surrounding blog-post and source-file links.

Suggested fix

Use Org-mode link syntax:

-and [this video](https://www.youtube.com/watch?v=G6a5G5i4gQU).
+and [[https://www.youtube.com/watch?v=G6a5G5i4gQU][this video]].