Documentation updates for v0.8.0

[tpatki]

Creating separate issue to track the documentation updates that didn't make it in v0.5.0 docs (see issue #238)

• A proper HPC power/energy annotated bibliography would be lovely
• When possible, add a section on overheads of using Variorum-annotated code at scale. We need to collect some data with and without variorum for this on a test app, such as LULESH or Pennant. Maybe do this on Lassen and Quartz
• Add a paragraph or two explaining each of the system software we integrate with, eg GEOPM, Flux, Caliper, Kokkos, LDMS.
• Also add data from Flux + LBANN, or Kokkos or Caliper integration with Variorum, that clearly shows application profiling for user applications

Integration updates

• PowerAPI: The initial integration is here: LLNL/variorum-integrations#1
• GEOPM: GEOPM Variorum JSON integration amarathe84/geopm#2
• QuickSilver integration: Get link from @kulnaman

Jessica's suggestions:

• MSRs, MSR-batches and what they include (Intel)
• msr-safe documentation needs to be added