Update readme.md

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: He-Pin

readme.md

@@ -292,7 +292,7 @@ To generate the static files without starting a server:
 
 The output is a single `index.html` file (with the Sjsonnet JS engine inlined) written to `out/playground/bundle.dest/`. You can open it directly in a browser — no server needed — or serve it with any static file server. The editor UI (CodeMirror) is loaded from a CDN at runtime, so an internet connection is required.
 
-## development
+## Development
 To compile the JVM version:
 
 ```bash