updating readme
Merge branch 'master' of github.com:chadkouse/ideavim

* 'master' of github.com:chadkouse/ideavim: (62 commits)
  updating to latest upstream
  Added 'Where to start' for contributors
  Note about Android Studio
  Bumped version
  Minor changes to README
  Note about Android Studio
  Revert "Fixed usages of deprecated platform API methods"
  Dropped JComboBox generics
  Fixed usages of deprecated platform API methods
  Use moved ListCellRendererWrapper for compatibility with IntelliJ builds 132.1052+
  Release notes
  Revert "Remove editor selection after undo"
  VIM-582 Fixed line comment and reformat commands with no visual selection
  Bumped version
  New URL for the plugin page
  More release notes
  Draft of release notes for 0.30
  Remove editor selection after undo
  Nullability annotations for 'cmd' parameter of execute() methods
  Removed unused argument
  ...