message: Update readme to point to the monnorepo
diff: +# Disclaimer
  -# Swift Debugger and REPL
  +The swift-lldb repository is frozen and is preserved for historical purposes only.
  +Active development is now happening in the following repository: https://github.com/apple/llvm-project
  -|| **Status** |
  -|---|---|
  -|**macOS** |[![Build Status](https://ci.swift.org/job/oss-lldb-incremental-osx-cmake/badge/icon)](https://ci.swift.org/job/oss-lldb-incremental-osx)|
  -|**Ubuntu 14.04** |[![Build Status](https://ci.swift.org/job/oss-lldb-incremental-linux-ubuntu-14_04/badge/icon)](https://ci.swift.org/job/oss-lldb-incremental-linux-ubuntu-14_04)|
  -|**Ubuntu 16.04** |[![Build Status](https://ci.swift.org/job/oss-lldb-incremental-linux-ubuntu-16_04/badge/icon)](https://ci.swift.org/job/oss-lldb-incremental-linux-ubuntu-16_04)|
  -|**Ubuntu 18.04** |[![Build Status](https://ci.swift.org/job/oss-lldb-incremental-linux-ubuntu-18_04/badge/icon)](https://ci.swift.org/job/oss-lldb-incremental-linux-ubuntu-18_04)|
  +# Swift Debugger and REPL
  **Welcome to the Swift Debugger and REPL!**
  