Clarify what should be committed in README

I understand the docs need lots of work[1] but I think
this line should be updated soon to include the decision
made in #123, even if a big rewrite is coming.  It has
confused me[2] and several other people[3].

[1]: #122 (comment)
[2]: #131 (comment)
[3]: http://stackoverflow.com/questions/26334220/should-i-commit-godeps-workspace-or-is-godeps-json-enough/26342342#26342342

fixes #131
closes #135

Readme.md

@@ -24,7 +24,7 @@ it's one command to start using:
 This will save a list of dependencies to the file Godeps/Godeps.json,
 and copy their source code into Godeps/_workspace.
 Read over its contents and make sure it looks reasonable.
-Then commit the file to version control.
+Then commit the whole Godeps directory to version control, [including _workspace](https://github.com/tools/godep/pull/123).
 
 #### Restore