Add some Koha documentation links to the README
Add some Koha documentation links to the README

Fixes #13

digibib/kohadevbox,KohaAloha/kohadevbox,joubu/kohadevbox,bywatersolutions/kohadevbox,mtompset/kohadevbox,wizzyrea/kohadevbox,mrenvoize/kohadevbox,mtompset/kohadevbox,wizzyrea/kohadevbox,KohaAloha/kohadevbox