SDP Guide Doc Updates:
* Fixed typos.
* Enhanced mandatory/nomandatory description.
* Added detail to instructions on using the `perforce-p4python` packcage,
and change reference from Swarm docs to the more general Perforce Packages
page.
* Refactored FAQ, Troubleshooting Guide, and Sample Procedures appendices
for greater clarity.
* Added Appendix on Brokers in Stack Topology