Create default Vimspector config (#46)

* Create a basic .vimspector.json for Java if one doesn't exist
  * Add the setting `java.debug.vimspector.config.createIfNotExists`
* Add a basic .editorconfig
* Improve the README doc
  * Add a quick start
  * Add new features
  * Add new settings
  * Add goals and non-goals
  * Add a simple main method debug launch example
* Upgrade dependencies
* Set generic return type for executeCommand

.editorconfig

@@ -0,0 +1,22 @@
+; EditorConfig is awesome: http://EditorConfig.org
+
+; top-most EditorConfig file
+root = true
+
+; base rules
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+; Dont remove trailing whitespace from markdown
+; files since it messes up newlines
+[*.md]
+trim_trailing_whitespace = false
+
+; Make does not work without tabs
+[Makefile]
+indent_style = tab