added exit shortcut for codemirror

buildroot-v86/board/v86/rootfs_overlay/root/opt/codemirror/codemirror

@@ -5,3 +5,4 @@ me="$(dirname $(readlink -f $0))"
 file="$(readlink -f "$1")"
 
 $me/codemirror.js "$file"
+echo "press ctrl-X to exit editor"

buildroot-v86/board/v86/rootfs_overlay/root/opt/codemirror/codemirror.js

@@ -87,6 +87,11 @@ AFRAME.registerComponent('codemirror', {
       }           
     })
     this.editor.setOption("theme", "shadowfox")
+    this.editor.setOption("extraKeys", {
+      "Ctrl-X": (cm) => {
+        this.el.emit('close',true) // window.js will react accordingly
+      }
+    })
     this.editor.updateFile = AFRAME.utils.throttle( (file,str) => {
       this.updateFile(file,str)
     }, 1500)