Add more detailed DOCUMENTATION

[sacOO7]

First of all, thank you for taking efforts to write the client. I am very greatful 👍 . Can you please more detailed doc about installation and usage of the client. I think it will be really helpful for other users. You can refer below functionality for the documentation.

https://github.com/sacOO7/socketcluster-client-java

[NuSkooler]

@sacOO7 I'm no long at the company this was built for and as such I'm not currently actively working on it. If I need WebSockets in C++ again, I'll likely pick up from there as it's BSD licensed. If there are specific areas you would like help/docs for I can attempt to put something together in my fork.