Start a wiki

[SWittouck]

Make a "quick start" section in the main README file and move demonstrations of more complicated analyses to a GitHub wiki.

Example of a more complicated analysis to explain in the wiki: creating a pangenome profile database for a hierarchical pangenome (see LEGEN pipeline for a detailed example):

1. Gather the pseudogenome sequences with the fetch module.
2. Build the profile database using the pseudopangenome (part of the hierarchical pan module output) and the pseudogenome sequences.