Allow documenting route parameters

[wilbrt]

Fixes #167

[akheron]

Parameters can have non-unique names, as long as they appear in a different "parts" of the request.

From the OpenAPI spec:

4.8.12 Parameter Object §
Describes a single operation parameter.

A unique parameter is defined by a combination of a name and location.

[...]

in | string | REQUIRED. The location of the parameter. Possible values are "query", "header", "path" or "cookie".

There are two options for solving this:

1. Instead of a single @reqparam tag, add separate tags @query, @header, @routeParam, @cookie to document parameters appearing in different places. (I used @routeParam instead of @path because typera exposes captured route parts in request.routeParams).
2. Add a more generic @param IN NAME DESCRIPTION. The IN part would be either query, header, path, or cookie, as per the OpenAPI spec.

I don't really have an opinion about which one is better.

[wilbrt]

Ah, I didn't think of that. The @reqparam tag has now been split into @query, @header, @routeParam and @cookie as suggested.

[akheron]

Great stuff!

One more thing: This now seems to set schema.example instead of description 🤔 There would also be example on the "top level" of the parameter.

Eventually users would probably want to set either description or example or both. I'm not sure how to solve this in a clean way. Adding JSDoc tags for descriptions and examples adds quite a bit of noise.

[wilbrt]

Works now as planned,I think. Not 100% sure about the current routeParam validation implementation.