Update NEWS for 0.2 and 0.3-wip

NEWs.md

@@ -1,7 +1,35 @@
 nanofmt
 =======
 
-Release 0.1.0
--------------
+Release 0.3 (WIP)
+-----------------
 
-- Initial release
+### Breaking Changes
+
+- Renamed `format_output` to `format_context`.
+- Custom formatter parsing now uses `format_parse_context`.
+
+### Features
+
+### Bug Fixes
+
+### Infrastructure
+
+- Switch from Catch2 to doctest for testing framework.
+
+Release 0.2
+-----------
+
+### Features
+
+- Added `NANOFMT_FLOAT` option to disable float support.
+- Support implicit conversion to `format_string`.
+
+### Bug Fixes
+
+- Correct `format_length` with integer format args (#54).
+
+Release 0.1
+-----------
+
+- Initial release.