docs: add change log

Author: boblat

changelog.d/20251121_171849_bobby.lat_arc4_contract.md

@@ -0,0 +1,40 @@
+<!--
+A new scriv changelog fragment.
+
+Uncomment the section that is right (remove the HTML comment wrapper).
+For top level release notes, leave all the headers commented out.
+-->
+
+<!--
+### Removed
+
+- A bullet item for the Removed category.
+
+-->
+
+### Added
+
+-   `algopy.Contract` as an alias for `algopy.arc4.ARC4Contract` to make ARC-4 contract the default option.
+
+### Changed
+
+-   Renamed `algopy.Contract` as `algopy.BaseContract` to be the base class for non ARC-4 contracts.
+
+<!--
+### Deprecated
+
+- A bullet item for the Deprecated category.
+
+-->
+<!--
+### Fixed
+
+- A bullet item for the Fixed category.
+
+-->
+<!--
+### Security
+
+- A bullet item for the Security category.
+
+-->