Rewrite or Move docs in examples/QIR/Simulation

[swernli]

The guides and sample code in examples/QIR/Simulation are for extending the old C++ QIR Runtime, which was removed as of https://github.com/microsoft/qsharp-runtime/pull/1087. These examples need to be rewritten for the new approach of writing a QIR backend using the Rust QIR standard library and would perhaps be better suited to live under https://github.com/qir-alliance/qir-runner. Once they have been refactored and moved there, they can be deleted from here.