Build termcap file

[Luflosi]

Since infocmp apparently can't generate a termcap file with all the capabilities, I let kitty do that instead. Do you think that's a good idea?

Note that I have not yet tested the resulting termcap file.

[kovidgoyal]

There's no point writing it out to a termcap file, since as far as I know, termcap dbs cant be read from random files. Instead just modify the FAQ entry to recommend doing something like

kitty +runpy "code to generate termcap" >> /etc/termcap

or whatever.

[Luflosi]

I just tested this, it doesn't work yet. I'll have to investigate a little more.