API documentation comments

It would be useful if the properties and classes had their xmldoc comments.

Many classes could really benefit from this and it shouldn't be much work for somebody who actually understands Hangfire deeply.

I know about the [api.hangfire.io](api.hangfire.io) project, but the documentation there is just not sufficient.

It makes me think if the poor documentation isn't a business decision to make users pay for plans with support.

Anyway, Hangfire is an amazing product and I believe this would improve it without much effort. How about starting with the basic configuration classes like `SqlServerStorageOptions`, `BackgroundJobServerOptions`, `DashboardOptions`?

Start by locating the basic configuration classes named in the issue: SqlServerStorageOptions, BackgroundJobServerOptions, and DashboardOptions. Review their public classes and properties, along with the existing API documentation conventions. Done means those types and members have useful XML documentation comments suitable for the generated API documentation.

Written by the indexing model from the issue text.