Update readme.

README.adoc

@@ -1,22 +1,26 @@
-= Portage repository "tastytea"
+= Portage repository “tastytea”
+:uri-portage: https://wiki.gentoo.org/wiki/Project:Portage
+:uri-gentoo: https://gentoo.org/
+:uri-eselect-repository: https://wiki.gentoo.org/wiki/Eselect/Repository
+:uri-layman: https://wiki.gentoo.org/wiki/Layman
+:uri-pgp-key: https://tastytea.de/tastytea.asc
 
-This is an unofficial repository for
+This is an unofficial repository for link:{uri-portage}[Portage],
-https://wiki.gentoo.org/wiki/Project:Portage[Portage],
+link:{uri-gentoo}[Gentoo]'s package manager.
-https://gentoo.org/[Gentoo]'s package manager.
 
 All ebuilds are marked as testing. All live-ebuilds have no keywords. I will
 delete ebuilds I no longer use.
 
 == Add this repository
 
-=== Using https://wiki.gentoo.org/wiki/Eselect/Repository[eselect-repository]
+=== Using link:{uri-eselect-repository}[eselect-repository]
 
 [source,shell]
 ----
 eselect repository enable tastytea
 ----
 
-=== Using https://wiki.gentoo.org/wiki/Layman[layman]
+=== Using link:{uri-layman}[layman]
 
 [source,shell]
 ----
@@ -29,7 +33,7 @@ I use PGP to sign commits and manifests.
 
 Fingerprint: `D5B4 C43B 48A8 79F6 3529  36E6 5934 6E0E A35C 67E5`
 
-Public key: https://tastytea.de/tastytea.asc
+Public key: link:{uri-pgp-key}[]
 
 [source,shell]
 ----