Initial project import

tools/v/vlib/yaml/README.md

@@ -0,0 +1,52 @@
+## Description
+
+`yaml` provides a pure-V YAML reader and writer for common configuration files.
+It supports nested mappings, sequences, flow-style collections, block scalars,
+tree access through `yaml.Any`, and generic struct encode/decode.
+
+The generic `encode`/`decode` path delegates to the main `json` module so it
+matches existing JSON field behavior, including `@[json: 'name']`.
+
+## Usage
+
+```v
+import yaml
+
+struct Config {
+	name    string
+	enabled bool
+	ports   []int
+}
+
+const config_text = '
+name: app
+enabled: true
+ports:
+  - 8080
+  - 9090
+'
+
+fn main() {
+	doc := yaml.parse_text(config_text)!
+	assert doc.value('ports[1]').int() == 9090
+
+	config := yaml.decode[Config](config_text)!
+	assert config.name == 'app'
+	assert yaml.encode(config).contains('"name": "app"')
+}
+```
+
+## File helpers
+
+```v
+import yaml
+
+struct Config {
+	name string
+}
+
+fn main() {
+	config := yaml.decode_file[Config]('config.yml')!
+	yaml.encode_file('config.out.yml', config)!
+}
+```