Polish microarray GSVA example

[jaclyn-taroni]

Purpose

Polishing the microarray GSVA example.

Issue addressed

For the microarray GSVA example, the following are being addressed:

• Enforcing comment character length limit (#406)
• Stopping row names from being printed for paged tables (#428)
• Adding the introductory paragraphs that are in every pathway analysis notebook (#371)

Comments/questions for the reviewer

Outside of copying over some of the changes to the microarray differential expression example with more than 2 groups (#427), I have not done much with the limma section.

[jaclyn-taroni]

I like the de-messy-ing of the design matrix column names. Good call.

Can't take credit for this, all @jashapiro on #427!