C++: Only include sum of LoC in the new non-alert summary queries for now.

Author: criemen

cpp/ql/src/Summary/LinesOfCode.ql

@@ -1,7 +1,7 @@
 /**
  * @id cpp/summary/lines-of-code
- * @name Total lines of C/C++ code
- * @description The total number of lines of C/C++ code across all files, including system headers and libraries.
+ * @name Total lines of C/C++ code in the database.
+ * @description The total number of lines of C/C++ code across all files, including system headers and libraries. This is a useful metric of the size of a database.
  * @kind metric
  * @tags summary
  */