added fullscreen button for notes and snippets

allows user to hide the sidebars for fullscreen editing

browser/main/Detail/MarkdownNoteDetail.js

@@ -30,7 +30,14 @@ class MarkdownNoteDetail extends React.Component {
         content: ''
       }, props.note),
       isLockButtonShown: false,
-      isLocked: false
+      isLocked: false,
+      fullScreen: {
+        status: false,
+        oldState: {
+          nd : 0,
+          mb : 0
+        }
+      }
     }
     this.dispatchTimer = null
 

browser/main/Detail/SnippetNoteDetail.js

@@ -48,7 +48,15 @@ class SnippetNoteDetail extends React.Component {
         description: ''
       }, props.note, {
         snippets: props.note.snippets.map((snippet) => Object.assign({}, snippet))
-      })
+      }),
+      fullScreen: {
+        status: false,
+        oldState: {
+          nd : 0,
+          mb : 0
+        }
+      }
+
     }
   }