Compatibility matrix should use unified data/presentation files

[harding]

For each wallet/service in the compat matrix, we have two files:

• A file in _data/compatibility/ with the wallet's characteristics
• A boilerplate file in en/compatibility/ that calls the template with the characteristic data

That's dumb. The idiot who designed it that way should be ashamed of himself. A better method would be to use a custom post type like we did for the topics with the _topics/en/ directory where we have two documents combined into a single file, a YAML data part and a Markdown part (which can be empty in this case). This eliminates the need for the boilerplate and ensures only a single file needs to be edited, renamed, or deleted when we want to make changes to a particular wallet or service.

This should be a pretty simple conversion.