Update TPC Project Page

[bbockelm]

Please review the contents of the TPC project page here: https://iris-hep.org/projects/tpc.html

Try to have the following

• Project description is up-to-date and reflects the current status of the project.
• One or two figures explaining the architecture of the project and scale / performance results (such as screenshots from monitoring or a figure reproduced from a figure), as applicable.
• Recent accomplishments (particularly if they are checking off an NSF milestone) and plans / research directions for the next year or so.
• Team section has all the right people listed.
• All relevant papers are listed under publications. Papers should acknowledge IRIS-HEP.
• All relevant presentations are uploaded. Presentations should acknowledge IRIS-HEP.

[bbockelm]

Did some writing and overhauled the top half of the page. Diego, I'll leave you to the rest.

[ddavila0]

I've created a PR with the updates: #758 but cannot merge it myself nor ask for a reviewer, Could you @bbockelm merge it please?