2.0 Complete engine rewrite

Full Changelog: 1.1...2.0

This is a major braking departure. The main user change is the new way to register jobs, which is now done by single jobs, and not in one big, and there is a way to update job schedule at runtime.

Also removed dependency on Rx and OptionsExtensions

Nuget Release

Full Changelog: 1.0...1.1

Release

Full Changelog: 0.1...1.0

Initial Release

Add various new files for cron job functionalities

These files contain various utility functions, classes, and configuration settings which are essential for the operation of cron jobs in the application. This includes classes for handling cron expressions, options for cron jobs, and extension methods for int32 and DateTime, among others. It also adds configuration files for the project.