a more concise explanation

* This removes an needless example (it should really be obvious what
  the text means).
* It also fixes an incomplete sentence, which also happens to have
  broken grammar.
be more concise, and simplify

* It should be obvious which file is referred to
* Fix a typo
* 'points at a string' is not ideal when referring to Python
Merge pull request #887 from tshepang/concise

be more concise; simplify; remove obvious info