Set LLVM 13 as the default

[idavis]

This PR sets the default version of LLVM to 13. This is a breaking change for consumers of the QIR. This PR includes changes to:

• Version bumped to 0.5.0a1 as this is a breaking change.
• Pipeline
  • Default linux build agent is Ubuntu 22.04
  • Windows installs llvm 13 for build
• Documentation now references Ubuntu 22.04 so that default llvm/clang tooling is available for LLVM 13
• Build script initializes vscode and cargo config files for command line and editor tooling support.
• manylinux and musllinux install to separate target directories for isolation.

[idavis]

closes #35