Clean readme

[AngelOnFira]

This cleans the readme file, and adds an issue template for people who want to request their game be added.

I think there are some improvements that could be made with some of the wording of the issue template.

[17cupsofcoffee]

Looks good! My only thought is that it might be good to have a template for the other categories as well? Or have one template with a drop down for what type of item you're submitting?

Some more info that may be worth working into the comments:

The TOML schema is the same for all of the categories, the main difference is just that ecosystem entries usually use the source field to automatically pull various bits of data from Crates.io or Github. Specifically, it will autofill:

• repository_url
• crate_url (crates source only)
• homepage_url (if they've set that on the crate/repo)
• description

These can all be overridden with the explicit options, though.

Also, we generally don't have images for crates/resources, as they don't look great in the single column layout those pages use.