Add changelog

Note v1 release.

CHANGELOG.md

@@ -0,0 +1,31 @@
+# Changelog
+
+*Major* changes are documented in this file.
+
+## [v1] - 2023-01-22
+
+### Added
+
+- Experiment in `python/ada-002.ipynb` showing decimal representations with 9
+  figures, and briefly explaining their significance.
+
+### Changed
+
+- Revise documentation, particularly `why.md`, to make clear that Base64
+  encoding is not required to prevent precision from being lost on the server
+  side.
+- Clarify how to use `compare/check.rb`.
+
+## [v0]
+
+*Initial release.*
+
+### Added
+
+- Structured explanation in `why.md`.
+- Bash, Python, and Java example code.
+- Ruby script to compare results.
+
+
+[v1]: https://github.com/EliahKagan/embed-encode/compare/v0...v1
+[v0]: https://github.com/EliahKagan/embed-encode/releases/tag/v0