Made clear how to make the precommit hook

There is a pre-commit hook set up step in the docs that references
a relative path. A line exemplifying where that command is run from
has been added to address the frequent question of "what is this
relative to"
Merge pull request #4 from perrito666/contributor_doc_updates

There is a pre-commit hook set up step in the docs that references
a relative path. The usual confusion is because the relative path
in ln is relative to where the link is created not to the current
path and therefore people thinks they have a folder missing.
A line exemplifying where that command is run from
has been added to address the frequent question of "what is this
relative to"