add shortform to keys

packages/core/src/Extension.ts

@@ -1,4 +1,4 @@
-import { Editor } from './Editor'
+import { Editor, Command } from './Editor'
 
 export default abstract class Extension {
 
@@ -39,11 +39,11 @@ export default abstract class Extension {
     return []
   }
 
-  keys(): { [key: string]: any } {
+  keys(): string | { [key: string]: Function } {
     return {}
   }
 
-  commands(): { [key: string]: any } {
+  commands(): { [key: string]: Command } {
     return {}
   } 
 

packages/core/src/ExtensionManager.ts

@@ -79,7 +79,17 @@ export default class ExtensionManager {
 
   get keymaps() {
     return collect(this.extensions)
-      .map(extension => extension.keys())
+      .map(extension => {
+        const keys = extension.keys()
+
+        if (typeof keys === 'string') {
+          return {
+            [keys]: () => this.editor.command(extension.name)
+          }
+        }
+
+        return keys
+      })
       .filter(keys => !!Object.keys(keys).length)
       .map(keys => keymap(keys))
       .toArray()