Corniel Nobel

How to decorate methods and types yet, I'm not sure, but it is worth a try. Closes #466

Introduce a generic type Interval

1

I've needed an interval (in the mathematical sense) quite sometimes now in my programming career. For my [Advent of Code](https://adventofcode.com/) puzzles I made a variant that works for integers, which...

For the continuous SVO's (like `Percentage` and `Amount`) it could be useful to have the `==` and `!=` operators also on the nullable variants.

See: https://devblogs.microsoft.com/dotnet/creating-aot-compatible-libraries/

For fixed/read-only lookups, the use of `FrozenDictionary` is preferable over a regular `Dictionary`. We should investigate where that can be applied.