Updated README

README.md

@@ -1,6 +1,62 @@
 # Vulcan API
 
 ## Description
-Python API for Vulcan E-journal system. It's based on the mobile app, so you can register it as a mobile device on the [site](https://uonetplus.vulcan.net.pl/).
+Python API for Vulcan e-journal system. It's based on the mobile app, so you need to register it as a mobile device on the site.
 
-![alt](https://i.imgur.com/AKBkOJq.png)
+![image](https://i.imgur.com/AKBkOJq.png)
+
+## Installation
+You can install `vulcan-api` by `pip`
+```
+pip install vulcan-api
+```
+
+Or manually
+```
+pip install flit
+git clone https://bitbucket.org/kapi2289/vulcan-api.git
+cd vulcan-api
+flit install
+```
+
+## Usage
+First, you need to register API as a mobile device on https://uonetplus.vulcan.net.pl/(symbol)
+
+![image](https://i.imgur.com/x03Aykd.png)
+
+![image](https://i.imgur.com/OVr5Px4.png)
+
+```python
+from vulcan import Vulcan
+import json
+
+# Vulcan.create(token, symbol, pin)
+cert = Vulcan.create('3S1GFG0P', 'gminaglogow', '059671')
+
+# Save certificate to a file
+with open('cert.json') as f:
+    f.write(json.dumps(cert))
+```
+
+When you have API already registered, you can now use it
+
+```python
+from vulcan import Vulcan
+import json
+
+# Load certificate from a file
+with open('cert.json') as f:
+    cert = json.loads(f.read())
+
+# Create a client
+client = Vulcan(cert)
+```
+
+API automatically selects first pupil, if you have more than one pupil you can get all of them, and set the default
+
+```python
+users = client.users()
+user = users[0]
+
+client.change_user(user)
+```