[DOC] Types of Contributions broken link

[loganthomas]

Brief Description of Fix

Currently, the docs have a link within CONTRIBUTING.rst the links types of Contributions to https://github.com/ericmjl/pyjanitor/blob/dev/CONTRIBUTION_TYPES.html

I would like to propose a change, such that now the docs links the above to the docs website (https://ericmjl.github.io/pyjanitor/CONTRIBUTION_TYPES.html)

Relevant Context

• Link to documentation page
• Link to exact file to be edited

[loganthomas]

@ericmjl
Suggested labels:

• docfix
• good first issue
• hacktoberfest-2020

If you agree, I can label for you 😄

[ericmjl]

@loganthomas you've got admin rights, and I trust your judgment here. Please go ahead! 😄

[Bhavna777]

I want to work on it.