Adds RegexNodes and route_params methods
Adds DynamicRoutes: regex, datatype, named & func
Simplifies DynamicRoutes & removes "Converters"

- Radically simplifies logic around dynamic routing.
- Replaces typealiases with named constructors.
- Removes "Converter" routes – no real use case / no simple
  way to inject functions.
Documents DyanmicRoutes & clarifies their syntax