Clarify --enable=all help text about whole-program analysis

Author: preenu91

cli/cmdlineparser.cpp

@@ -1754,8 +1754,9 @@ void CmdLineParser::printHelp() const
         "    --enable=<id>        Enable additional checks. The available ids are:\n"
         "                          * all\n"
         "                                  Enable all checks. It is recommended to only\n"
-        "                                  use --enable=all when the whole program is\n"
-        "                                  scanned, because this enables unusedFunction.\n"
+        "                                  use --enable=all when the entire program is\n"
+        "                                  scanned, since some checks (e.g. unusedFunction)\n"
+        "                                   require whole-program analysis and may otherwise produce many false positives.\n"
         "                          * warning\n"
         "                                  Enable warning messages\n"
         "                          * style\n"