Requested Changes for Editor Knossos Implementation (#129)

* placeholder

* max length & placeholder

* Accept editor comment conflict

* integrate requested features

* null check for ref

* Change prompt for image upload

* change filter for proper input blocking

* Add spoiler button

* change url of helper link

* shallow resource link style

* resource link inherit site style

* detach preview styling from markdown-body style

* remove sizing dependance on global styles

* Bump 0.6.5

lib/helpers/codemirror.ts

@@ -22,6 +22,10 @@ const toggleCodeBlock: Command = ({ state, dispatch }) => {
   return toggleAround(state, dispatch, codeBlockMark, codeBlockMark)
 }
 
+const toggleSpoiler: Command = ({ state, dispatch }) => {
+  return toggleAround(state, dispatch, '||', '||')
+}
+
 const toggleHeader: Command = ({ state, dispatch }) => {
   return toggleLineStart(state, dispatch, '# ')
 }
@@ -342,6 +346,7 @@ const commands = {
   toggleItalic,
   toggleStrikethrough,
   toggleCodeBlock,
+  toggleSpoiler,
   toggleHeader,
   toggleHeader2,
   toggleHeader3,