Adds a feed_channel implementation which reflects a feed's specific
settings per channel.
Also added an UnparsedTimedScore to score which allows parsing to score
from db in a controlled fashion.
Creates a fetch mod for fetching remote rss content.
This implementation is barebones and not great since it doesn't pass any
compression or timestamp information.
Adds SQLX for database management, and an Adapter interface for
interacting with it. Through the type "AdapterPool"
Creates an initial_schema with everything I think I'll need.
Adds Chrono package
Adds a "Result" type to lib.rs
creates helpful type aliases for Score, Boost, and Gravity.
Creates a "TimedScore" which is a value and time data for calculating
score over time. There are two forms of this, Boosted and Decaying.
Since a Score can either be decaying over time or have been boosted
recently and be kept from decaying for some time.
Also implements a BoostedScore and a DecayingScore, which are both
TimedScores which represent the different states. These are important
because you can't boost a BoostedScore for instance.
