I have added a page for partial object caching -
https://cwiki.apache.org/confluence/display/TS/Partial+Object+Caching
This will be changing because as I typed it up I realized I had a much better
understanding of cache mechanics which is changing my view on the best options
to do this.
I have also updated the tiered storage proposal, which is in the architectural
docs historically and I don't have the energy to move it. At some point the
update will appear here -
https://trafficserver.readthedocs.org/en/latest/arch/cache/tier-storage.en.html
but you can grab it from git any time.
