use <pre>-formatted blocks for code in scaladoc and only escape non-code blocks
use <pre>-formatted blocks for code in scaladoc and only escape non-code blocks

Summary:
IDEA was complaining about carrot's in regexp patterns.
Dollar signs were being escaped everywhere, include regexp patterns- making them harder to read.

Test Plan: sbt ramlGenerate doc

Reviewers: jasongilanfarr, aquamatthias

Reviewed By: aquamatthias

Subscribers: marathon-team

Differential Revision: https://phabricator.mesosphere.com/D193

guenter/marathon,janisz/marathon,janisz/marathon,gsantovena/marathon,gsantovena/marathon,guenter/marathon,meln1k/marathon,mesosphere/marathon,mesosphere/marathon,gsantovena/marathon,janisz/marathon,mesosphere/marathon,guenter/marathon,meln1k/marathon,meln1k/marathon,mesosphere/marathon,Caerostris/marathon,natemurthy/marathon,natemurthy/marathon,guenter/marathon,Caerostris/marathon,Caerostris/marathon,mesosphere/marathon,Caerostris/marathon,natemurthy/marathon,Caerostris/marathon,gsantovena/marathon,meln1k/marathon,meln1k/marathon,janisz/marathon,guenter/marathon,gsantovena/marathon,janisz/marathon