Merge branch 'create-instance-on-alpha' into 'master'

docs: add create instance on alpha

See merge request !71

docs/easycozy/create-instance.md

+# Create an instance
+
+To create a cozy instance on alpha, you need to connect to SSH to alpha.
+
+## 1. Create the instance on alpha
+
+```bash
+cd easy-cozy/
+./create-instance.sh jean
+```
+
+The [`create-instance.sh`](https://forge.grandlyon.com/pocs/cozy/easy-cozy/-/blob/master/create-instance.sh?ref_type=heads) script will create a new instance and install ecolyo and related konnectors on it.
+
+:::danger Copy the configuration link
+
+You need to copy the configuration link to the instance. We will use it later to set the password of the instance.
+
+> Open this url on a browser to configure your instance https://jean.cozy.self-data.alpha.grandlyon.com?registerToken=AZERTY
+
+:::
+
+## 2. Add the instance subdomains to atrium
+
+- Go to https://atrium.self-data.alpha.grandlyon.com/ and connect with credentials provided by the team.  
+- Edit the "Cozy" app
+  
+You need to add the subdomains that will allow you to access apps of the created instance.
+
+To generate the subdomains :
+
+```bash
+cd /opt/atrium
+./generate-subdomains.sh
+# jean,ecolyo.jean,home.jean,settings.jean
+```
+
+Add the result of this command to the existing list of subdomains and save.
+
+:::note Wait for reboot
+Saving will reboot atrium. This usually takes a minute.
+:::
+
+## 3. Configure your instance
+
+Once Atrium is has rebooted, you can access the link you copied in step 1. and define your password.