Overview of ACR TR duties vs PBP duties, analyses to be created.

Why is this change being made?

Adds more transparency and clarity to the Annual Comp Review page by providing details on what TR does vs PBPs, what analyses are created (and details on these).

Still TODO:

• Read over what I've already added, fill in details, check formatting, clarify where unclear.
• Add section for managers on determining the proper holistic increase for their team member based on performance factor, benchmark % increase, and location factor % increase.

@brittanyr This still needs more work, but would appreciate for you to take a quick pass and highlight anything you think especially needs work, should be done a different way, isn't working, etc. I'll tag in others once I don't feel it's incomplete.

Author Checklist

• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Assign this change to the correct DRI
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to your manager.
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies.
  • If the changes relate to any part of the project other than updates to content and/or data files please make sure to ping @gl-static-site-editor in a comment for a review and merge. For example changes to .gitlab-ci.yml, JavaScript/CSS/Ruby code or the layout files.