Fix discrepency in definition of Context type in 1.2 API documentation

[kriswest]

Minor Issue

The definition of the Context type in the API documentation does not match the spec or source code.

Area of Issue

[ ] App Directory
[x] API
[x] Context Data
[ ] Intents
[ ] Use Cases
[ ] Other

Issue Description:

When defining Context, the API documentation state that:

The API specification allows this to be any object, but typically this is supposed to be a context data object adhering to the [Context Data Specification]

This is not actually true, the API specification doesn't actually define Context, but does make use of typed context throughout (the only actual requirement on the structure of the Context object in the context specification is that it has a string type field). For example, it doesn't make sense to a typed context or intent listener without the type being present.

The source code provided with the specification specifically imports the Context definition from the Context specification, hence, the documentation is at odds with both the specification and source code and should be corrected.

Additional Context:

this comes from the early days of FDC3, where API was disconnected from Context Data, and the idea was that the API is not opinionated about the shape of the data, and it could be ANY object. Hence, you could fdc3.broadcast(object). But you COULD use fdc3 context data envelope and be more specific.

This changed in FDC3 1.1 and the documentation was not updated to reflect this.