Update changelog

Lots of changes in this PR, but only a couple are user-facing. All other
changes can be considered performance improvements that do not change
functionality.

CHANGES.md

@@ -2,6 +2,18 @@
 
 ## __NEXT__
 
+### Features
+
+* `augur.io.read_metadata`: A new optional `columns` argument allows specifying a subset of columns to load. The default behavior still loads all columns, so this is not a breaking change. [#1294][] (@victorlin)
+* filter: Add a new argument `--query-columns` allowing users to explicitly specify columns and data types for when automatic type inference behaves unexpectedly. [#1294][] (@victorlin)
+
+### Bug Fixes
+
+* filter: The order of rows in `--output-metadata` and `--output-strains` now reflects the order in the original `--metadata`. [#1294][] (@victorlin)
+* filter, frequencies, refine: Performance improvements to reading the input metadata file. [#1294][] (@victorlin)
+    * For filter, this comes with increased writing times for `--output-metadata` and `--output-strains`. However, net I/O speed still decreased during testing of this change.
+
+[#1294]: https://github.com/nextstrain/augur/pull/1294
 
 ## 24.1.0 (30 January 2024)