Missing Documentation for ContinuationTokenSpecification

[philip-reed]

We are continuously addressing and improving the SDK, if possible, make sure the problem persist in the latest SDK version.

Describe the bug
Missing Documentation for ContinuationTokenSpecification.

To Reproduce
Section missing from docs site here:
https://ievangelist.github.io/azure-cosmos-dotnet-repository/4-queries/specification-pattern/

Expected behavior
An explanation on how this type is used.

Actual behavior
N/A

Environment summary
N/A

Additional context
I stumbled on this missing documentation when trying to understand how the ContinuationTokenSpecification should be used for initial calls where there isn't a continuation token available yet. (The continuationToken parameter to the constructor is not nullable).

[mumby0168]

@philip-reed I think this was done pre-nullables and probably should be updated, the docs should also be added to to clarify the use of this type, in the meantime checkout the samples here:

https://github.com/IEvangelist/azure-cosmos-dotnet-repository/blob/2a9b39b8446051a71e7176977abd224a51aeae9b/samples/Microsoft.Azure.CosmosRepository/Specification/SpecificationPagingSamples.cs#LL42C8-L42C88

[philip-reed]

It looks like ContinuationToken property is nullable on the BaseSpecification, so this hints that I should be ok to pass a null through on the ctor. Maybe you're right @mumby0168 and this just wants nullable adding to the ContinuationTokenSpecification continuationToken parameter?