feat(Command): Add Command.takesValue(b) setter

This patch introduces a new setter for `Command.setting.takes_values`
previously you had to use either `Command.takesSingleValue` or `Command.takesNValues`
or set it manually.

src/Command.zig

@@ -94,7 +94,12 @@ pub fn takesNValues(self: *Command, arg_name: []const u8, n: usize) !void {
     if (n > 1) arg.valuesDelimiter(",");
 
     try self.addArg(arg);
-    self.setting.takes_value = true;
+    self.takesValue(true);
+}
+
+/// Specifies that the command takes value. Default to 'false
+pub fn takesValue(self: *Command, b: bool) void {
+    self.setting.takes_value = b;
 }
 
 /// Specifies that argument is required to provide. Default to `false`