Update README

README.md

@@ -1 +1,21 @@
-# gtfs-realtime-rust
+# gtfs-realtime-rust
+
+This is a Rust learning exercise to build a REST server that dynamically launches and manages a set of async tasks. These tasks fetch a GTFS-Realtime feed from an endpoint supplied during a POST call.
+
+## Running Locally
+```
+cargo test
+cargo run
+```
+
+## Sample Feed
+```
+{
+    "name": "MTA A Division",
+    "frequency": 30,
+    "url": "https://api-endint.mta.info/Dataservice/mtagtfsfeeds/nyct%2Fgtfs",
+    "headers": {
+        "x-api-key": "<key_goes_here>"
+    }
+}
+```