proposal: go/doc: Support for bulleted lists #7873

Presently, the best practice when enumerating something in godoc is to use a
pre-formatted section.  For example:

"""
This library has the following caveats:
  * It requires the caller to invoke the method
    only on odd-numbered days
  * It may crash your computer.
"""

I think it would improve godoc (HTML) readability to recognize and format bulleted lists
as <ul>'s instead.  The recognition could be narrowly defined to avoid mistakenly
formatting blocks that were not intended to be lists.

I propose a list is recognized as:
- An indented (pre-formatted) block, 
- .. that consists of 2 or more list items
- .. and that consists only of list items

and a list item is defined as:
- Consecutive lines
- .. where the first line begins with "- " or "* "
- .. that terminate on blank lines.

This can be implemented with minimal disruption to the existing code.  Here is a CL:
https://golang.org/cl/91830044

Here are some before/after examples from popular package docs: 

http://godoc.org/code.google.com/p/gorilla/mux
http://192.241.149.161:8080/pkg/code.google.com/p/gorilla/mux

http://godoc.org/code.google.com/p/gorilla/sessions
http://192.241.149.161:8080/pkg/code.google.com/p/gorilla/sessions

http://godoc.org/code.google.com/p/gorilla/schema
http://192.241.149.161:8080/pkg/code.google.com/p/gorilla/schema

http://godoc.org/code.google.com/p/gogoprotobuf/gogoproto
http://192.241.149.161:8080/pkg/code.google.com/p/gogoprotobuf/gogoproto

http://godoc.org/github.com/davecgh/go-spew/spew
http://192.241.149.161:8080/pkg/github.com/davecgh/go-spew/spew

http://godoc.org/code.google.com/p/go.text/collate/colltab#pkg-constants
http://192.241.149.161:8080/pkg/code.google.com/p/go.text/collate/colltab#pkg-constants