Remove lex, format, and minify from README

[aluttik]

There's not a lot of reason to include lex, format, and minify in the README. They just clutter up the docs, create confusion about the point of crossplane, and keeping them in creates a responsibility for devs to maintain them. I don't think we should remove the capabilities from the tool, though, to maintain backwards compatibility.

This would also solve https://github.com/nginxinc/crossplane/issues/90.

[ornj]

I agree that there is little reason to include information in the readme that can otherwise be obtained from the command line with --help. Documentation of crossplane's API would be better placed as docstrings where they would be easier to keep up to date and provide additional value when help() is used in the repl.

[AnotherZane]

I agree that there is little reason to include information in the readme that can otherwise be obtained from the command line with --help.

Well yes, but some new users might not have the cli tool installed. I think they should have a way to know that these sub commands exist.

I think moving it to a wiki page would be a better idea than entirely removing it.

[aluttik]

I would recommend getting rid of these subcommands entirely, but to maintain backwards compatibility they should at least work until a new major version comes out.