added json doc-comment

crates/api-grub/src/json.rs

@@ -2,6 +2,21 @@
 use serde_json::{json, Value};
 use integr_structs::api::v3::{Metric, MetricOutput};
 
+/// A JSON-parser struct 
+/// 
+/// Using in metric extracting from Server Response 
+/// with metrics mechanism
+/// 
+/// # Example
+/// 
+/// ```
+/// use api-grub::json::JsonParser;
+/// use use integr_structs::api::v3::Metric;
+/// 
+/// let json = b""flat1" : { "room1" : { "rt_tempo" : "+16" }}".to_vec();
+/// 
+/// assert!(!JsonParser::parse(vec![Metric::template()], json).is_empty());
+/// ```
 pub struct JsonParser;
 
 impl JsonParser {