README: Remove redundant section
There are two sections about hackage.head. Only the second one mentions the need for cabal update, which just threw me off ( see ghc#20872 (comment 399761)). So let’s remove the first one to avoid confusion.
There are two sections about hackage.head. Only the second one mentions the need for cabal update, which just threw me off ( see ghc#20872 (comment 399761)). So let’s remove the first one to avoid confusion.