chore: Remove BenchmarkDotNet.Disassembler project

[filzrev]

This PR remove BenchmarkDotNet.Disassembler project.
Because it looks like no be used after migrated to use IInProcessDiagnoser for disassembler.

[timcassell]

Need to update https://benchmarkdotnet.org/articles/contributing/disassembler.html#how-to-debug-the-disassembler

[filzrev]

Need to update https://benchmarkdotnet.org/articles/contributing/disassembler.html#how-to-debug-the-disassembler

I've removed this document on latest commit.
Because How it works section seems not needed because x86/x64 disassembler is migrated to run in-process.

Currently, there are following deserializers, I thought it's not needed documented on contributing pages.

• IntelDisassembler (x86/x64)
• Arm64Disassembler
• MonoDisassembler

How to debug the disassembler section also not needed.
It can debug deserializer by using --inProcess mode.