docs: Missing @param() decorator API Docs

[virkt25]

https://apidocs.strongloop.com/@loopback%2fopenapi-v2/v/0.1.0/

The above API Docs is missing documentation for the @param decorator but the docs have documentation for other decorators such as @get(), @post(), etc.

The decorator is documented in code. Seems like the tool generating the Docs is failing to parse it correctly possibly because the decorator is @param which is also reserved for documenting is as well.

[kjdelisle]

For beta, we have the http://loopback.io/doc/en/lb4/Decorators.html#parameter-decorator section, which provides some detail on how to use the @param decorator.

Until we have a proper fix for the typedoc parsing issue, we should avoid making hacky fills in the regular documentation (or anywhere, really!)