Add VSCode and EditorConfig files (#782)

.editorconfig

@@ -0,0 +1,10 @@
+# see http://editorconfig.org/
+
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+insert_final_newline = true

.vscode/extensions.json

@@ -0,0 +1,7 @@
+{
+  "recommendations": [
+    "rebornix.ruby",
+    "misogi.ruby-rubocop",
+    "EditorConfig.editorconfig"
+  ]
+}

.vscode/settings.json

@@ -0,0 +1,8 @@
+{
+  "editor.formatOnSave": true,
+  "files.trimTrailingWhitespace": true,
+
+  // Rubocop settings
+  "ruby.rubocop.configFilePath": ".rubocop.yml",
+  "ruby.rubocop.onSave": true
+}