* Add SshCommand.ExecuteAsync
After the previous change (#1423), this basically entails swapping out the
IAsyncResult for a TaskCompletionSource and hooking up the cancellation/timeout
logic.
As with the prior Begin/End implementation, the initiation of the command
(SendExecRequest) happens synchronously, so there's a bit of room for improvement
there, but otherwise it is the Task-based async that we know and like.
I chose to make it void (Task)- returning instead of string like in the existing
overloads, so that OutputStream is not automatically consumed (and encoded as a
string) when that may not be desired. As in #650, I was initially considering
changing the other overloads to be void-returning as well, but decided that it was
not worth the break since most people will probably want to change over to
ExecuteAsync anyway.
* Update examples
---------
Co-authored-by: Wojciech Nagórski <wojtpl2@gmail.com>
- Update README to point to https://sshnet.github.io/SSH.NET rather than the CHM file
- Add a CONTRIBUTING.md with some how-tos
For https://sshnet.github.io/SSH.NET:
- Use the repo README as the landing page to keep them in sync
- Combine the API-per-TFM pages to just one "API" page
- Add a couple more examples
- Add a GitHub link in the header.
