Describe the bug

The grammar is missing the nameof operator

Requirements

• I've read and understood the Contributing guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.
• I've searched for any related issues and avoided creating a duplicate issue.

To Reproduce

Grammar does not contain a definition for the nameof operator which prevent a highlighting query from targeting that.

$d[nameof C] = 4;

Which makes a query like this fail

[ 
  "nameof" 
] @keyword.operator

Expected behavior

I expect the nameof operator to be listed in the grammar