Add package idna to the index

index/idna.mk

@@ -0,0 +1,7 @@
+PACKAGES += idna
+pkg_idna_name = idna
+pkg_idna_description = Erlang IDNA lib
+pkg_idna_homepage = https://github.com/benoitc/erlang-idna
+pkg_idna_fetch = git
+pkg_idna_repo = https://github.com/benoitc/erlang-idna
+pkg_idna_commit = master