feat(ws): send history data and update data with web socket

Added following logic:
1. New clients receive 15 entry history from history file
2. After that, every 10 seconds when new entry is generated it is sent
out to all connected clients

backend/nodemon.json

@@ -0,0 +1,4 @@
+{
+  "watch": ["."],
+  "ignore": ["node_modules/**", "data.json"]
+}