Add colors to --help

[starsep]

I used clap-cargo as it's easy to use and provides sensible default styles.
User can disable colors via NO_COLOR=1 environment variable

before	after	NO_COLOR=1

[tmccombs]

fd isn't a clap plugin, so using clap-cargo for it doesn't seem appropriate.

Also, doesn't fd already have colored help output?

[starsep]

fd isn't a clap plugin, so using clap-cargo for it doesn't seem appropriate.

Ok, I will remove dependency as it is actually quite easy to do without it.

Also, doesn't fd already have colored help output?

At the moment it doesn't. It had before upgrade to clap v4 which is using bold for headers and no longer uses colors by default, even with color feature enabled