Updated README.

Author: xneg

README.md

@@ -2,3 +2,46 @@
 Python simulator of distributed system
 
 [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/xneg/distributed-game/main?labpath=%2Fsrc%2Fsandbox_notebook.ipynb)
+
+# Web-version
+https://xneg.github.io/distributed-game/
+
+# How to
+You need to implement your own algorithm inheriting [class Node](https://github.com/xneg/distributed-game/blob/main/src/engine/node.py).
+There are two abstract methods processing read and write requests:
+```python
+@WebServer.endpoint(message_type=ClientReadRequest)
+@abc.abstractmethod
+def process_read_request(self, request):
+    pass
+
+@WebServer.endpoint(message_type=ClientWriteRequest)
+@abc.abstractmethod
+def process_write_request(self, request):
+    pass
+```
+You can see examples [here](https://github.com/xneg/distributed-game/tree/main/src/algorithms).
+
+# Engine
+![diagram_2](https://user-images.githubusercontent.com/5748886/180388311-e00628d9-0408-4e77-8689-0edc327f0975.jpg)
+This diagram shows communication between two `WebServers`.
+WebServer contains three main methods:
+
+* send_message(receiver_id, message)
+
+* add_message(message)
+
+* process()
+
+The `send_message(receiver_id, message)` method creates a `Signal` (1) object that contains the "message packet" itself and the ID of the receiving server.
+In fact, `Signal` after a certain number of steps will call the `add_message(message)` (2) callback already on the recipient side.
+
+The `add_message(message)` method sends a message to one of the server endpoints (3) with the help of typing, decorators and a bit of "pythonic" magic.
+Web servers use signals instead of calling each other's methods directly to mimic the asynchronous nature of network.
+The signal can have an arbitrary execution time, moreover, it is possible to make the signal "lost" by simulating network breaks.
+
+![diagram_1](https://user-images.githubusercontent.com/5748886/180388323-8a26f1a4-e4e1-41fe-85a9-c982fe55d46b.jpg)
+This diagram shows implemented system. The client only knows about the gateway.
+Gateway acts as a proxy between the client and the nodes of the system, it knows about anything. The gateway forwards client requests to nodes via round-robin (the first request comes to the first node, the second - to the second).
+Then the nodes exchange messages with each other and send the response back to the gateway, which returns it to the client.
+All the arrows on the diagram are, in fact, signals.