chore: Changelog for 0.9.4 (#3379)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Maximilian Roos <5635139+max-sixty@users.noreply.github.com>

CHANGELOG.md

@@ -1,8 +1,11 @@
 # PRQL Changelog
 
-## [unreleased]
+## 0.9.4 — 2023-08-24
 
-**Language**:
+0.9.4 is a small release with some improvements and bug fixes in the compiler
+and `prqlc`. And, the documentation and CI are continually being improved.
+
+This release has 110 commits from 9 contributors. Selected changes:
 
 **Features**:
 
@@ -13,8 +16,6 @@
 
 **Fixes**:
 
-- `prqlc` no longer displays a prompt when piping a query into its stdin
-  (@max-sixty, #3248).
 - S-strings within double braces now parse correctly (@max-sixty, #3265)
 
 **Documentation**:
@@ -29,7 +30,9 @@
 
 **Integrations**:
 
-- Add a minimal example for use with Zig (@vanillajonathan, #3372)
+- `prqlc` no longer displays a prompt when piping a query into its stdin
+  (@max-sixty, #3248).
+- Add a minimal example for use `prql-lib` with Zig (@vanillajonathan, #3372)
 
 **Internal changes**:
 
@@ -48,6 +51,9 @@
 
 **New Contributors**:
 
+- @FinnRG, with #3292
+- @sitiom, with #3353
+
 ## 0.9.3 — 2023-08-02
 
 0.9.3 is a small release, with mostly documentation, internal, and CI changes.