INSTALL.md: Document existence of packages in some more OS's

[danielshahaf]

• https://openports.se/shells/zsh-syntax-highlighting
• http://cvsweb.netbsd.org/bsdweb.cgi/pkgsrc/shells/zsh-syntax-highlighting/
• Might as well link to https://repology.org/project/zsh-syntax-highlighting/versions so people can quickly check whether their distro's covered or not
• Consider adding repology badges (see INSTALL.md: Document existence of packages in some more OS's #753 (comment) below)

Kudos to Matthew for making the former happen in the first place :-)

[hexxdump]

Is this issue still open? If so, can I work on it?

[danielshahaf]

Yes to both questions. Welcome aboard!

I personally haven't got much time right now for reviews, though. Matthew, Julien, how about you?

[hexxdump]

@danielshahaf, @phy1729, can you please review the change

[hexxdump]

@danielshahaf, @phy1729, can you please review the change

can you pls review? @danielshahaf @phy1729

[danielshahaf]

Guys, please? Trivial change, new contributor. I'd review but I've got too many balls in the air :(

[cho-m]

One optional modification for 3rd item would be to embed the package status as badge inside page like:

[![Packaging status](https://repology.org/badge/vertical-allrepos/zsh-syntax-highlighting.svg)](https://repology.org/project/zsh-syntax-highlighting/versions)

[danielshahaf]

Thanks for the suggestion. I'll add it it to the checklist momentarily so we don't forget it. In the meantime, here are other badges repology offers:

As to the vertical badge, I'm not sure I like using up so much vertical real estate when we could just link to repology. What do others think?