[lldb] update eArgTypeScriptLang description to mention lua

--script-language python and --script-language lua are both valid now.

Reviewed by:	JDevlieghere

Differential Revision:	https://reviews.llvm.org/D77241
diff --git a/lldb/source/Interpreter/CommandObject.cpp b/lldb/source/Interpreter/CommandObject.cpp
index 01fa867..f1f17db 100644
--- a/lldb/source/Interpreter/CommandObject.cpp
+++ b/lldb/source/Interpreter/CommandObject.cpp
@@ -1091,7 +1091,7 @@
     { eArgTypeRunArgs, "run-args", CommandCompletions::eNoCompletion, { nullptr, false }, "Arguments to be passed to the target program when it starts executing." },
     { eArgTypeRunMode, "run-mode", CommandCompletions::eNoCompletion, { nullptr, false }, "Help text goes here." },
     { eArgTypeScriptedCommandSynchronicity, "script-cmd-synchronicity", CommandCompletions::eNoCompletion, { nullptr, false }, "The synchronicity to use to run scripted commands with regard to LLDB event system." },
-    { eArgTypeScriptLang, "script-language", CommandCompletions::eNoCompletion, { nullptr, false }, "The scripting language to be used for script-based commands.  Currently only Python is valid." },
+    { eArgTypeScriptLang, "script-language", CommandCompletions::eNoCompletion, { nullptr, false }, "The scripting language to be used for script-based commands.  Supported languages are python and lua." },
     { eArgTypeSearchWord, "search-word", CommandCompletions::eNoCompletion, { nullptr, false }, "Any word of interest for search purposes." },
     { eArgTypeSelector, "selector", CommandCompletions::eNoCompletion, { nullptr, false }, "An Objective-C selector name." },
     { eArgTypeSettingIndex, "setting-index", CommandCompletions::eNoCompletion, { nullptr, false }, "An index into a settings variable that is an array (try 'settings list' to see all the possible settings variables and their types)." },