add readme

README.md

+Implemented Abstractions:
+### Chat
+##### props
+  `id<int>`
+
+### User
+##### props
+  `id<int>`
+  
+  `chat<Chat>`
+  
+  `isAdmin<bool>` — return true if user is admin of the group
+
+##### methods
+  `send(text: string, [Choose])` — send PM to user. Really it is not useful due to bot can not initiate chat with user
+  
+  `ban(duration: string)` — ban user in group
+  
+  `unban()` — unban user. this would not read user to the group (bot api does not support this action)
+  
+  `capture(Event[]): <CaptureStop>` — capture all next users messages in the messages group and begin to match them only against specified `Event list`
+
+### Message
+##### props
+  `raw` — original data from API
+  
+  `raw.message_id<int>`
+  
+  `user<User>`
+  
+  `chat<Chat>`
+  
+  `from<Message>` — if message is a reply — it would contains previous message. TODO: rename it
+
+##### methods
+  `send(text: string)` — send new message to the messages channel
+  `reply(text: string)` — send reply to the message
+  `remove()` — remove message from channel
+
+### Choose
+ > abstraction for generating custom in-chat-buttons
+
+TODO: refactor code to standalone module.
+
+Example of rules:
+```js
+// Admin can ban user by replying to his\her massage with `\ban`. Works only if user is not admin.
+Reply('/ban')
+    .then(async function( message ){
+        if( (await message.user.isAdmin()) && !(await message.from.user.isAdmin())){
+          message.from.reply(L('ban', {...message.from.user}));
+          message.from.user.ban();
+        }
+    })
+Answer('/say {{$kokoko}}')
+    .then((message, match)=>{
+        message.send(match.kokoko)
+    })
+```