Link to the CommonMark website to explicitly reference what it is, and to help users unfamiliar with it to discover and navigate to it.
CommonMark is mentioned very early in the README. Here it is a subheadline. I decided to not link here but in this features section instead where it is listed as one of the features. The subheadline seems more fitting as a short, pure text for those knowing about it.
The link is to the main website rather than the specification as users unfamiliar with it will want to land on the landing page with a description of what it is rather than a technical specification. The specification page does not immediately and obviously link back to the main website.
The shortened term spec is being extended to its full word specification for clarity and discoverability.
This makes three changes to backlinks:
- Inserts a space before `<a href='…'>↩</a>` to make it look better
- Uses hexadecimal references (`&#x…;`) instead of decimal references for clarity
- Adds U+FE0E VARIATION SELECTOR 15 to the ↩ to suppress emojification on both iOS and Edge on Windows
If variation selector 15 isn't appended to the ↩, then the return arrow will show up as an emoji on iOS and Edge for Windows. The Pandoc project has already run into this quirk as documented on https://github.com/jgm/pandoc/issues/5469 and they've pushed a change for their Markdown processor already.