Split contributing docs from user guide

Author: jim-parry

contributing.md

@@ -5,7 +5,7 @@
 
 We expect all contributions to conform to our style guide, be commented (inside the PHP source files), 
 be documented (in the user guide), and unit tested (in the test folder). 
-There is a [Contributing to CodeIgniter](./contributing) section in the repository which describes the contribution process; this page is an overview.
+There is a [Contributing to CodeIgniter](./contributing/index.rst) section in the repository which describes the contribution process; this page is an overview.
 
 ## Issues
 

contributing/index.rst

@@ -2,16 +2,13 @@
 Contributing to CodeIgniter
 ###########################
 
-.. toctree::
-    :titlesonly:
-
-    guidelines
-    workflow
-    signing
-    internals
-    documentation
-    PHP Style Guide <styleguide>
-    ../DCO
+- `Contribution guidelines<./guidelines.rst>`_
+- `Contribution workflow<./workflow.rst>`_
+- `Contribution signing<./signing.rst>`_
+- `Framework internals<./internals.rst>`_
+- `CodeIgniter documentation<./documentation.rst>`_
+- `PHP Style Guide <./styleguide.rst>`_
+- `Developer's Certificate of Origin<../DCO.txt>`_
 
 CodeIgniter is a community driven project and accepts contributions of code
 and documentation from the community. These contributions are made in the form