Dashboard loading (#142)

* Fixed: Loading indicator never appears
Added: Loading indicator to dashboard when loading first results

* Less assumptions

* Fixes: Image uploads not working

* Fixes #136 - Keyboard shortcuts should work when editor is not focused

* Allow images to be dragged anywhere on document editor

* Fixes #137 - vertical alignment

* Restore shortcuts with editor focus

* Restore 'e' to edit current document
Fixed up ? to open keyboard shortcuts

* wip

* LoadinglistPlaceholder

* WIP

* Refactor

* DRY logic

frontend/scenes/Document/components/LoadingPlaceholder/index.js

@@ -0,0 +1,3 @@
+// @flow
+import LoadingPlaceholder from './LoadingPlaceholder';
+export default LoadingPlaceholder;