Populate wiki homepage

[jwMaxwell]

Is your feature request related to a problem? Please describe.
The wiki home page is completely empty. This makes the MoDiBo project unwelcoming.

Describe the solution you'd like
Create a wiki home page for the .github repository, which details the following:

• What MoDiBo is
• What MoDiBo does
• Who MoDiBo is for
• How to install and setup MoDiBo
• How to install MoDiBo plugins and where to find them
• How can users contribute
• Brief introductions and links to other pages on the wiki