Support providing version of `crx3` tool

[przemoc]

trafficstars

I realized there is no easy way to confirm version of crx3 tool. Please consider fixing it.

Typically it is done via options: -V, --version (upper-case V, because lower-case v is typically used for increasing verboseness)

But you could also do it via command: version

[mmadfox]

Okay. I will add it soon, and it is a very useful command

[przemoc]

Thanks. Looks like it got implemented in ac085bf24b19.

$ crx3 version
crx3 tools version v1.6.0

I believe we can close it now.