chore: Adding changelog

Update CHANGELOG.rst

Co-authored-by: María Fernanda Magallanes <[email protected]>

CHANGELOG.rst

@@ -0,0 +1,26 @@
+Change Log
+----------
+
+..
+   All enhancements and patches to edx-organizations will be documented
+   in this file.  It adheres to the structure of https://keepachangelog.com/ ,
+   but in reStructuredText instead of Markdown (for ease of incorporation into
+   Sphinx documentation and the PyPI description).
+
+   This project adheres to Semantic Versioning (https://semver.org/).
+.. There should always be an "Unreleased" section for changes pending release.
+
+
+Unreleased
+~~~~~~~~~~
+
+Added
+_____
+
+* Added the changelog file
+
+
+[v6.13.0] - 2024-04-02
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+* Previous history can be found in github https://github.com/openedx/edx-organizations/tags