link to contributing guide

and suggest that users work on a separate fresh copy of the code if they want to contribute pull requests.

Author: edoddridge

doc/getting_started/getting_started.rst

@@ -105,7 +105,7 @@ Be forewarned, this will only work if you have not modified ANY of the files in
 
 3. **Fully embracing the power of git!**
 
-Git offers many tools to help organize and track changes in your work.  For example, one might keep separate projects on different branches, and update the code separately (using ``git pull``) on these separate branches. You can even make changes to code in the MIT repo tree; when git then tries to update code from upstream (see :numref:`git_setup`), it will notify you about possible conflicts and even merge the code changes together if it can. You can also use ``git commit`` to track user modifications in code (but not for the purpose of contributing such changes to the main code repo), to help you track what you are modifying in your simulations over time. See here (...) for more information and how to use git effectively to manage your workflow.
+Git offers many tools to help organize and track changes in your work.  For example, one might keep separate projects on different branches, and update the code separately (using ``git pull``) on these separate branches. You can even make changes to code in the MIT repo tree; when git then tries to update code from upstream (see :numref:`git_setup`), it will notify you about possible conflicts and even merge the code changes together if it can. You can also use ``git commit`` to help you track what you are modifying in your simulations over time. If you're planning to submit a pull request to include your changes, you should read the contributing guide in :numref:`chap_contributing`, and you may find it easier to work on a separate, fresh copy of the code. See here (...) for more information and how to use git effectively to manage your workflow.
 
 (we should be more specific above, need to agree how so however)