fix: add empty activationEvents to manifest

Required, even though unpopulated, to package the extension.
Language contribution automatically activates extension as required.

Author: traunts

.DS_Store

@@ -24,6 +24,7 @@
     "Cortex Command Community Project"
   ],
   "main": "dist/packages/client/src/extension",
+  "activationEvents": [],
   "contributes": {
     "configuration": {
       "type": "object",