Complete 'Challenges' section

[jaimiebutton]

As part of our SWRS documentation for execs, we'll need to communicate the current challenges with using SWRS.

Acceptance Criteria:

• [x] Take stock of challenges documented from Elliott's report
• [x] List out any challenges not outlined in the report
• [x] Theme challenges

[jaimiebutton]

Hey @pbastia + @dleard , I've done my pass of the challenges section and themed them out. Feel free to do a pass too :)