Debugging instructions simplified

[jtulach]

• I am trying to improve Enso VSCode Extension (which depends on this extension) to support testing of Enso sources
• While working on Report test execution progress enso-org/enso#14720 I had huge problems setting debugging up
  • the current instructions seem complex and a bit obsolete
• At the end I decided to simplify it - the result is in this PR

vscode$ npm run nbcode

• shall be everything one needs to debug Java running in code
  • the code is started with fresh data and extension directories
  • as such it should be isolated enough from any personal setup
• I am able to install enso.vsix into the started code instance and then debug both
  • Apache NetBeans Language Server extension
  • as well as Enso VSCode Extension
• I am debugging from NetBeans IDE attaching to port 8000