added missed $etrap, fix for #121

Author: daimor

src/providers/completion/systemVariables.json

@@ -29,6 +29,18 @@
     ],
     "link": "/csp/docbook/DocBook.UI.Page.cls?KEY=RCOS_vestack"
   },
+  {
+    "label": "$ETRAP",
+    "alias": ["$ETRAP", "$ET"],
+    "documentation": [
+      "Contains a string of ObjectScript commands to be executed when an error occurs.\n",
+      "```objectscript\n",
+      "$ETRAP\n",
+      "$ET\n",
+      "```\n"
+    ],
+    "link": "/csp/docbook/DocBook.UI.Page.cls?KEY=RCOS_vetrap"
+  },
   {
     "label": "$HALT",
     "alias": ["$HALT"],