initial plans and limits

These pricing tiers are a starting point. We don't know enough for accurate pricing tiers, or even structurally what makes most sense (teams paying per user, for example). As a starting point, the plus plan is perhaps overpriced, but it's easier to start high and reduce price later. Similarly, limits are more aggressive as it's easier to give later than to take away from users. We know the least about team/business use cases, and it's perhaps underpriced, but it's probably structurally off entirely. Overall, we're trying to optimize for simplicity and options, knowing these tiers are probably wrong.

Besides groups, we're not yet differentiating based on features. All plans get all features, which would be better reflected in marketing material and pricing page.

## Basic
* Free
* 10 commands
* rate limited to 60 run/min
* run limits:
* 512 MB mem
* 512 MB images
* 30 sec runtime

## Plus
* $10/mo
* 100 commands
* rate limited to 300 run/min
* run limits:
* 2GB mem
* 2GB images
* 5 minute runtime

## Team
* $50/mo per group
* 100 commands in a group
* rate limited to 900 run/min
* run limits:
* 4GB mem
* 4GB images
* 30 minute runtime

Team gets you a group and limits apply to commands in that group. You can be a free user and part of an team group, where you'd get access to the commands in the group and have your own limited 10 free commands. This is similar to GitHub, where organizations have their own plans separate from the users.