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/styles/constants.js

@@ -50,6 +50,7 @@ export const color = {
   /* Light Grays */
   smoke: '#F4F7FA',
   smokeLight: '#F9FBFC',
+  smokeDark: '#E8EBED',
 
   /* Misc */
   white: '#FFFFFF',