chore(main): release 1.20.0 (#87)

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>

Author: release-please[bot]

CHANGELOG.md

@@ -0,0 +1,13 @@
+# Changelog
+
+## 1.20.0 (2024-03-11)
+
+
+### Features
+
+* Add handling for updating stored columns on indexes ([eea1b22](https://github.com/cloudspannerecosystem/spanner-schema-diff-tool/commit/eea1b222f1532b942c2b31b1377d4eba090e5c86))
+
+
+### Bug Fixes
+
+* library should released as 1.20.0 ([#91](https://github.com/cloudspannerecosystem/spanner-schema-diff-tool/issues/91)) ([efd280c](https://github.com/cloudspannerecosystem/spanner-schema-diff-tool/commit/efd280cc64d217443d8a19660aec8677339da65e))