Merge pull request #2 from mxsasha/patch-1

Improve compatibility with Python <3.10

Author: fangpenlin

wtforms_bootstrap5/registry.py

@@ -10,7 +10,7 @@
 from .helpers import traverse_base_classes
 
 # Union type of form element
-FormElement = Field | Form
+FormElement = typing.Union[Field, Form]
 # Type for form element renderer
 FormElementRenderer = typing.Callable[["RenderContext", FormElement], Markup]