TCurl tiers of help

[kriskowal]

tcurl -h should provide usage, enumerating the combinations of short flags.

tcurl --help should provide long usage, enumerating short and long flags and possible combinations of use, and a one line summary of each rule.

man tcurl should provide the full man page with the short usage in the synopsis and the long form explanation of each individual combination and option with all caveats.

TCurl should provide an install script to cover installation of the man page on Darwin and Linux.

[Raynos]

@kriskowal

The install script is npm i tcurl -g which does the right thing if the "man" key is set in the package.