fix isnull typo and formatting

docs/api/models/helpers/pydantic.md

@@ -5,7 +5,7 @@
 #### create\_pydantic\_field
 
 ```python
-create_pydantic_field(field_name: str, model: Type["Model"], model_field: Type["ManyToManyField"]) -> None
+create_pydantic_field(field_name: str, model: Type["Model"], model_field: "ManyToManyField") -> None
 ```
 
 Registers pydantic field on through model that leads to passed model
@@ -38,32 +38,6 @@ field_name. Returns a pydantic field with type of field_name field type.
 
 `(pydantic.ModelField)`: newly created pydantic field
 
-<a name="models.helpers.pydantic.populate_default_pydantic_field_value"></a>
-#### populate\_default\_pydantic\_field\_value
-
-```python
-populate_default_pydantic_field_value(ormar_field: Type["BaseField"], field_name: str, attrs: dict) -> dict
-```
-
-Grabs current value of the ormar Field in class namespace
-(so the default_value declared on ormar model if set)
-and converts it to pydantic.FieldInfo
-that pydantic is able to extract later.
-
-On FieldInfo there are saved all needed params like max_length of the string
-and other constraints that pydantic can use to build
-it's own field validation used by ormar.
-
-**Arguments**:
-
-- `ormar_field (ormar Field)`: field to convert
-- `field_name (str)`: field to convert name
-- `attrs (Dict)`: current class namespace
-
-**Returns**:
-
-`(Dict)`: updated namespace dict
-
 <a name="models.helpers.pydantic.populate_pydantic_default_values"></a>
 #### populate\_pydantic\_default\_values
 
@@ -76,7 +50,7 @@ dictionary of the class. Fields declared on model are all subclasses of the
 BaseField class.
 
 Trigger conversion of ormar field into pydantic FieldInfo, which has all needed
-paramaters saved.
+parameters saved.
 
 Overwrites the annotations of ormar fields to corresponding types declared on
 ormar fields (constructed dynamically for relations).