[TW-1461] Provide with a more complete default taskrc file

_Renato Alves on 2014-11-15T21:47:51Z says:_

Some of the most useful taskwarrior options are hidden behind configuration options. Even relatively experienced users will be unaware of some of these or of what they affect.

Newer users will most likely face the .taskrc file before ever touching the man page and will try to get around with what's included.

By providing a more complete taskrc where options can either be commented or set to their default value, we can show users what their taskrc file could look like and how they could customize taskwarrior to better suit their needs.

In practice it could be an complement to the man page focused on functional examples instead of detailed explanations.