docs re-orgnization

docs/app-dev/subscribing-to-events-via-websocket.md

@@ -0,0 +1,28 @@
+# Subscribing to events via Websocket
+
+Tendermint emits different events, to which you can subscribe via
+[Websocket](https://en.wikipedia.org/wiki/WebSocket). This can be useful
+for third-party applications (for analysys) or inspecting state.
+
+[List of events](https://godoc.org/github.com/tendermint/tendermint/types#pkg-constants)
+
+You can subscribe to any of the events above by calling `subscribe` RPC
+method via Websocket.
+
+```
+{
+    "jsonrpc": "2.0",
+    "method": "subscribe",
+    "id": "0",
+    "params": {
+        "query": "tm.event='NewBlock'"
+    }
+}
+```
+
+Check out [API docs](https://tendermint.github.io/slate/#subscribe) for
+more information on query syntax and other options.
+
+You can also use tags, given you had included them into DeliverTx
+response, to query transaction results. See [Indexing
+transactions](./indexing-transactions.md) for details.