fix: override browser shift-esc in command mode (#100)

Author: ianhi

schema/plugin.json

@@ -135,6 +135,11 @@
       "keys": ["Shift Escape"],
       "command": "notebook:enter-command-mode"
     },
+    {
+      "selector": ".jp-Notebook.jp-mod-commandMode",
+      "keys": ["Shift Escape"],
+      "command": ""
+    },
     {
       "selector": ".jp-NotebookPanel[data-jp-vim-mode='true'] .jp-Notebook:focus",
       "keys": ["Shift M"],