Version information

[lovasko]

Hello,

I have some good news and some bad news.

Good news: I was able to build the 2.0 on FreeBSD/aarch64, so I guess it can be added to the list of platforms where Herbie works! Both racket and rust are installed from the default package system in versions 8.9 and 1.70.

Bad news: it was non-trivial to ascertain what the version of my herbie binary is! Options -v or --version do not exist, and help text displayed with -h and --help does not show the version of Herbie. I only found out through the following string: Please specify a Herbie tool, such as herbie web. See <https://herbie.uwplse.org/doc/2.0/options.html> for more.. My suggestion would be to add a --version option, but also display the text in the help text in the header.

[pavpanchekha]

That's a good idea, and not hard to add. When you say "display the text in the help text in the header", what do you mean?