[LUA] Update example to show correct list index handling

[Local9]

As Lua starts its index at 1 and not 0, some of the example code is leading to confusion when being used. We should review the code in place for List Items and check the starting index value is 1 as per Lua indexing, and that any examples follow suit.

• Check UIMenuListItem index handling on creation to make sure the correct value is being used
• Update example.lua to have the correct starting index values