Fix the editor lock button layout

browser/main/Detail/MarkdownNoteDetail.js

@@ -380,6 +380,7 @@ class MarkdownNoteDetail extends React.Component {
               onMouseDown={(e) => this.handleLockButtonMouseDown(e)}
             >
               <img styleName='iconInfo' src={imgSrc} />
+              {this.state.isLocked ? <span styleName='tooltip'>Unlock</span> : <span styleName='tooltip'>Lock</span>}
             </button>
 
           return (

browser/main/Detail/MarkdownNoteDetail.styl

@@ -13,6 +13,24 @@
 
 .control-lockButton
   topBarButtonRight()
+  position absolute
+  right 225px
+  &:hover .tooltip
+    opacity 1
+
+  .tooltip
+    tooltip()
+    position absolute
+    pointer-events none
+    top 35px
+    right -10px
+    width 50px
+    z-index 200
+    padding 5px
+    line-height normal
+    border-radius 2px
+    opacity 0
+    transition 0.1s
 
 .trashed-infopanel
   position relative