Address 2.0 website issues.

[mike-ferguson]

Addressed the issues I am tagged under in here. As this PR is in web and 431 is on vision, I cannot PR onto it directly.

Specifically, this PR:

• Has clearer error messages on invalid zip failures
• Applies styling to invalid_zip.html and already_submitted.html
• Adds a picture of a correct submission package to invalid_zip failures
• Refactors some of the invalid_zip logic to be more coherent
• Removes brain/base models option for vision, but keeps public option
• Adds type hints and docstrings to invalid_zip methods (originally written awhile ago without them)
• Adds styling to vision submission to make it inline with vision
• Adds dedicated page to warn user not to submit a tutorial file
• Adds tutorial file to tutorial
• Updates tutorial to tell users to not actually submit the file
• Removes old navbar boilerplate code from html pages
• Overhauls Tutorial Main page styling to match themes
• Overhauls Quickstart page styling to match themes
• Overhauls Deep Dive 1 page styling to match themes
• Corrects Deep Dive 1 material to remove changing identifiers, etc
• Overhauls Deep Dive 2 page styling to match themes
• Overhauls Deep Dive 3 page styling to match themes
• Update font for leaderboard side panels
• fix resubmission job name from run_benchmarks to score_plugins
• reject all submissions >50MB
• Change Team -> Contributors, link to here
• PoInt Support (Footer) to Community page

[mike-ferguson]

Updated styling for an example faulty submission (models folder is empty):

[kvfairchild]

Some minor changes/clarifications, but at a higher level: I'm not sure if it makes sense to keep the deep dive tutorial the way it currently is structured, which (even if we're not actually making the submission) is geared towards creating a duplicate of an existing model under a different identifier. We could maybe just drop the identifier changing activities and have it be just a walkthrough of the example submission?

[kvfairchild]

Unfortunately I don't have as much time as I'd like to spend on this review, so while it generally looks good to me, I'm holding out approval for now and hoping a few other sets of eyes can make up the difference!

[mike-ferguson]

addressed all changes

[mike-ferguson]

For some reason Git was showing an unresolved issue when there was none, so I had to dismiss your previous review @mschrimpf, but all your changes were indeed addressed

already addressed