fish: add page

[EmilyGraceSeville7cf]

See this issue for details.

[chrisallenlane]

Hi, @EmilySeville7cfg

I appreciate the effort that went into this, but I'm going to decline to merge this one.

Most of these commands are simple POSIX commands that are covered by other cheatsheets (echo, read, etc), and interested users will know to search those cheatsheets as necessary.

Presumably, fish users will be familiar with the basics of using their shell, so I don't see the value in creating a "tutorial" for it, so to speak.

Thanks for the effort regardless.

[EmilyGraceSeville7cf]

@chrisallenlane

Can I treat it as «Warn contributors while reviewing there PRs when they describe non POSIX complaint shells»? 🤔

[BarbzYHOOL]

Presumably, fish users will be familiar with the basics of using their shell, so I don't see the value in creating a "tutorial" for it, so to speak.

same for every program...