Url links inside parenthetical statements are not interpreted as such

[rlmark]

If you create a standard url link inside a parenthetical statement, the links may not be rendered as actual links.

For example the following doc block will fail to interpret the first link as a valid link:

docRepro = {{
  Link link link blah ([myLink](www.google.com), [anotherLink](www.google.com))
}}

If the parenthetical is not immediately started with a link, you are able to successfully incorporate url links:

linkNotAtBeginning = {{
  Text text blah (something something [myLink](www.google.com) blah blah blah)
}}

A transcript is attached with the doc code capable of producing the issue, but the issue is best seen in the local ui or unison share.

parentheticalLink.md

[andreystepanov]

Here's another example of similar issue, where parser fails to understand braces ( ) in URLs.

Live example of Bytes.flatten.doc in base library:

https://share.unison-lang.org/@unison/base/code/releases/2.12.0/latest/terms/Bytes/flatten

Where rope link defined as:

[rope](https://en.wikipedia.org/wiki/Rope_(data_structure))

Parser need to be smarter about certain cases or URLs. ( and ) is totally valid characters in URL and doesn't need to be URL-encoded.

But i understand that it might be difficult to implement in the parser, which looks for closing ) while parsing links.

[andreystepanov]

Meanwhile i fixed doc link via contribution, by using %28/%29 encoded braces.

https://share.unison-lang.org/@unison/base/contributions/15

[andreystepanov]

Instead of dealing with markdown parser for links, maybe we can just extend Doc data-type:

unique type Doc
  = ...
  | Link Doc Doc
  | ...
  | ...

This way it might be easier to link images and other kind of documentation elements too.

[sellout]

Duplicate of #2483.