docs: typo fix ugh

Co-authored-by: Steve Piercy <[email protected]>

src/colander/__init__.py

@@ -499,7 +499,7 @@ class Range:
  specified, it must be a string. The string may contain the
  replacement targets ``${min}`` and ``${val}``, representing the
  minimum value and the provided value respectively. If not
- provided, ``min_err` defaults to ``'${val} is less than minimum value
+ provided, ``min_err`` defaults to ``'${val} is less than minimum value
  ${min}'``.
 
  ``max_err`` is used to form the ``msg`` of the