Create a wiki for ob docs repo

[DinithiDiaz]

We can create a wiki for the ob-docs repo to share the Documentation Guidelines & Best Practices which will be useful for open banking content contributions.

This is already being used in Choreo [1] and APIM [2] docs and I feel this will improve the quality of open banking content contributions. We can maintain this in the OB docs repo apart from the OB Documentation Process documentation which is maintained internally.

I will start this effort after confirming with the leads.

References:

[1] https://github.com/wso2/docs-choreo-dev/wiki/
[2] https://github.com/wso2/docs-apim/wiki/
[3] https://github.com/wso2-enterprise/asgardeo-docs/wiki
[4] https://docs.google.com/document/d/1TF0Sd2T_N105o-jyVa6z-DsiArSk_PDJtfFWSSsdO5c/edit
[5] https://github.com/okta/okta-developer-docs/wiki