Make sure code blocks in docstrings get formatted correctly

src/django_segments/models/segment.py

@@ -27,6 +27,9 @@ class AbstractSegment(models.Model, metaclass=AbstractSegmentMetaclass):
     and foreign key field instances in the concrete subclass.
 
     Examples:
+
+    .. code-block:: python
+
         class MySegment(AbstractSegment):
             segment_span = models.ForeignKey(MySpan, on_delete=models.CASCADE)
 

src/django_segments/models/span.py

@@ -27,7 +27,10 @@ class AbstractSpan(models.Model, metaclass=AbstractSegmentMetaclass):
     When the concrete subclass is created, the initial_range_field and current_range_field attributes set to the range
     field instances. These attributes can be used to access the range field instances in the concrete subclass.
 
-    Examples:
+    Example:
+
+    .. code-block:: python
+
         class MySpan(AbstractSpan):
             my_range_field = DateTimeRangeField()
             initial_range_field_name = 'my_range_field'