feat: support --fake for aerich upgrade (#398)

* feat: support `--fake` for aerich upgrade

* Add `--fake` to downgrade

* tests: check --fake result for aerich upgrade and downgrade

* Update readme

* Fix unittest failed because of `db_field_types` changed

* refactor: improve type hints and document

CHANGELOG.md

@@ -4,9 +4,13 @@
 
 ### [0.8.2]**(Unreleased)**
 
+#### Added
+- feat: add --fake to upgrade/downgrade. ([#398])
+
 #### Fixed
 - fix: inspectdb raise KeyError 'int2' for smallint. ([#401])
 
+[#398]: https://github.com/tortoise/aerich/pull/398
 [#401]: https://github.com/tortoise/aerich/pull/401
 
 ### [0.8.1](../../releases/tag/v0.8.1) - 2024-12-27