Kwargs for plotting with descriptions and sorted alphabetically

Author: lfenzo

src/mplfinance/_arg_validators.py

@@ -274,11 +274,16 @@ def _kwarg_not_implemented(value):
     raise NotImplementedError('kwarg NOT implemented.')
 
 def _validate_vkwargs_dict(vkwargs):
-    # Check that we didn't make a typo in any of the things
-    # that should be the same for all vkwargs dict items:
+    """
+    Check that we didn't make a typo in any of the things
+    that should be the same for all vkwargs dict items:
+
+    {kwarg : {'Default': ... , 'Description': ... , 'Validator': ...} }
+    """
     for key, value in vkwargs.items():
-        if len(value) != 2:
-            raise ValueError('Items != 2 in valid kwarg table, for kwarg "'+key+'"')
+        # has been changed to 3 to support descriptions
+        if len(value) != 3:
+            raise ValueError('Items != 3 in valid kwarg table, for kwarg "'+key+'"')
         if 'Default' not in value:
             raise ValueError('Missing "Default" value for kwarg "'+key+'"')
         if 'Validator' not in value: