Update README.md formatting
Enable SQLite foreign keys and delete video files on video delete
Process the video asynchronously and add proper processing message
Switch to named SQL parameters
Switch to sqlite

This commit enables using SQLite as the database engine. This greatly
simplifies the workflow:
- A separate Docker environment for development is not needed as
SQLite is not client-server based.
- Manual installations/deployments are much easier.

Main changes:
- Update the schema and queries to be SQLite compatible
- Update relevant golang code interacting with the database
- Move SQL files from sql/ to db/ as to enable embedding the schema

Other changes:
using go:embed.
- Move config.toml, videos/, temp-upload/ and db.sqlite into data/,
for Docker volume mounting purposes: Trying to mount db.sqlite when it
doesn't exist creates a directory with the same name.
- Update README.md
Add resolution option
Fix some docker and config stuff
Fix temp-upload directory not existing
Reduce Dockerfile size
Fix CORS AllowedMethods
Implement GET /videos/byChannel/{channelname}
Fix GLIBC version issues with docker and implement /static
Remove TODO.org (using basecamp now)
Fix cookie properties
Implement GET /channel