Add on-enter handler

Now, typing doc comments is much more pleasant

editors/code/src/commands/index.ts

@@ -2,6 +2,7 @@ import * as applySourceChange from './apply_source_change';
 import * as extendSelection from './extend_selection';
 import * as joinLines from './join_lines';
 import * as matchingBrace from './matching_brace';
+import * as on_enter from './on_enter';
 import * as parentModule from './parent_module';
 import * as runnables from './runnables';
 import * as syntaxTree from './syntaxTree';
@@ -13,5 +14,6 @@ export {
     matchingBrace,
     parentModule,
     runnables,
-    syntaxTree
+    syntaxTree,
+    on_enter,
 };