pages.sr.ht: depend on mailcap

This fixes pages.sr.ht#13 because it installs the MIME
database in `/etc/mime.types`, as expected by Go's
`mime.TypeByExtension` function. The small built-in
table used by Go when the MIME database was not found
did not contain an entry for the `.txt` extension.

pages.sr.ht: use new Makefile in APKBUILD

pages.sr.ht: upgrade to 0.4.8

pages.sr.ht: upgrade to 0.4.4

pages.sr.ht: new package