Dated back in dyweb/Ayi#17, never fully utilized godoc, just Func does func

• examples for using libraries
  • some example is runnable examples are same as tests, except you specify output (and it can be unordered)
• doc for interfaces, might not add those XXX implements xx interface
  • only added a few
• links to real application that is using gommon, go.ice, ayi, benchhub, xephon-k (though in some sense, they are not that real world since I'm the only the user and the only developer)

Optional

• command line tool for refreshing all the packages on godoc, by default, if no body visits, it won't get refreshed, and often show stale doc

Ref

• https://github.com/fluhus/godoc-tricks
• https://blog.golang.org/examples
• https://blog.golang.org/godoc-documenting-go-code
• http://elliot.land/post/godoc-tips-tricks