[unicode_entry] Add more information about setting XCompose
[unicode_entry] Add more information about setting XCompose

Also add information about using ibus-daemon.

MasterDuke17/doc,perl6/doc,dmaestro/doc,stmuk/doc,antquinonez/doc,tbrowder/doc,stmuk/doc,dmaestro/doc,dmaestro/doc,stmuk/doc,tbrowder/doc,antquinonez/doc,gfldex/doc,jonathanstowe/doc,dmaestro/doc,stmuk/doc,tbrowder/doc,gfldex/doc,antquinonez/doc,stmuk/doc,jonathanstowe/doc,perl6/doc,gfldex/doc,dmaestro/doc,jonathanstowe/doc,antquinonez/doc,gfldex/doc,MasterDuke17/doc,MasterDuke17/doc,MasterDuke17/doc,jonathanstowe/doc,perl6/doc,jonathanstowe/doc,perl6/doc,tbrowder/doc,antquinonez/doc,gfldex/doc,perl6/doc