update README.md & syntax/go.vim comments to reflect the fact that
functions, methods & structs are not highlighed by default anymore
fix typo in comment
Merge pull request #227 from michael-go/master

update README to help users enable syntax highlight for functions, methods & structs
Merge branch 'master' of https://github.com/fatih/vim-go

* 'master' of https://github.com/fatih/vim-go:
  fix typo in comment
  update README.md & syntax/go.vim comments to reflect the fact that functions, methods & structs are not highlighed by default anymore