[Doc] Add --log cmdline option to manpage (house-keeping)

[giantclambake]

Although covered elsewhere, the amiberry manpage should pronounce all cmdline options.

@midwan ~ query: does --log provide more detail than using 'log to file'? If so, then the line below should read 'Enable full log output to console'.... because that's what you'll be getting (not just a redirect of amiberry.log ) Perhaps I'm just being a pedant yet again.... =)

Might you please include something like the following snippet into the amiberry manpage when you get a moment, just to bring it inline with wrt other docs?

TIA

.B --log
Enable log output to console.
.TP

[midwan]

The log output is the same, only redirected to the console instead.