style.lua(9): Add some additional notes about naming and commas

camelCase tends to be preferred for function identifiers, while
internal_underscores are preferred for variable identifiers. This convention
makes it a little bit easier to eyeball whether variable/function usage is
correct.

The optional commas for final table values are preferred to reduce chances
for error.

share/man/man9/style.lua.9

@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd February 20, 2018
+.Dd February 25, 2018
 .Dt STYLE.LUA 9
 .Os
 .Sh NAME
@@ -83,6 +83,30 @@ Single-line conditional statements and loops should be avoided.
 .Pp
 .Ic local
 variables should be preferred to global variables in module scope.
+internal_underscores tend to be preferred for variable identifiers, while
+camelCase tends to be preferred for function identifiers.
+.Pp
+If a table definition spans multiple lines, then the final value in the table
+should include the optional terminating comma.
+For example:
+.Bd -literal
+-- No terminating comma needed for trivial table definitions
+local trivial_table = {1, 2, 3, 4}
+
+local complex_table = {
+	{
+		id = "foo",
+		func = foo_function, -- Trailing comma preferred
+	},
+	{
+		id = "bar",
+		func = bar_function,
+	},	-- Trailing comma preferred
+}
+.Ed
+.Pp
+This reduces the chance for errors to be introduced when modifying more complex
+tables.
 .Pp
 Multiple local variables should not be declared
 .Sy and