example/zig-formatter: show how to use formatters from libghostty (#9407)

example/zig-formatter/README.md

@@ -0,0 +1,24 @@
+# Example: stdin to HTML using `vtStream` and `TerminalFormatter`
+
+This example demonstrates how to read VT sequences from stdin, parse them
+using `vtStream`, and output styled HTML using `TerminalFormatter`. The
+purpose of this example is primarily to show how to use formatters with
+terminals.
+
+Requires the Zig version stated in the `build.zig.zon` file.
+
+## Usage
+
+Basic usage:
+
+```shell-session
+echo -e "Hello \033[1;32mGreen\033[0m World" | zig build run
+```
+
+This will output HTML with inline styles and CSS palette variables.
+
+You can also pipe complex terminal output:
+
+```shell-session
+ls --color=always | zig build run > output.html
+```