build documentation with correct path for ssh_filter_btrbk

[calestyo]

Hey.

I think it would be nice if at least here: https://github.com/digint/btrbk/blob/af2d7b2c99bac7c5af2f9b2c5f0b1947be525597/doc/ssh_filter_btrbk.1.asciidoc?plain=1#L48 the pathname would match that where it's actually installed.

Does asciidoc provide any replacement mechanism or should I make something with sed and rename the file to .in?

Possibly also here: https://github.com/digint/btrbk/blob/af2d7b2c99bac7c5af2f9b2c5f0b1947be525597/README.md?plain=1#L554-L561

OTOH, that should be directly readable, so maybe just hardcode /usr/share/btrbk/scripts/ssh_filter_btrbk.sh.

Cheers, Chris.