Resolve "Write API documentation"

Closes #2 (closed)

docs/api_documentation.rst

 API Documentation
 =================
 
-Coming soon!
+End points:
+
+Encryption:
+
+TODO: document post data
+
+``GET /encryption``
+  Returns the status of the encryption (whether or not you have an encrypted
+  partition)
+``POST /encryption/init``
+  Encrypts the disk with a password if there are no encrypted disks
+
+  Post data: ``{"password": password}``
+``POST /encryption/unlock``
+  Decrypts the disk using a password and boots the machine
+
+  Post data: ``{"password": password}``
+``POST /encryption/remove``
+  Brings the VPS in a state where the disk is not encrypted and booting does not
+  require a password (does not change the initrd to a "regular" initrd)
+
+  Post data: ``{"password": password}``
+``POST /encryption/selfdestruct``
+  Removes the encryption master key, effectively deleting the encrypted data
+  permanently.
+
+Encryption keys
+
+``GET /encryption/keys``
+  List luks password slots
+``POST/PUT /encryption/keys/{slot}``
+  Add/change a luks slot to a new password. {slot} corresponds to a slot id
+  listed by ``GET /encryption/keys``.
+
+  Post data: ``{"password": password, "new-password": new-password}``
+``DELETE /encryption/keys/{slot}``
+  Delete a password from a luks slot
+
+SSH keys with access to the initrd:
+
+``GET /ssh/keys``
+  List SSH keys in the ``/root/authorized_keys`` file
+``POST/ssh/keys``
+  Add a key to the authorized_keys file
+
+  Post data: ``{"ssh-key": ssh-key}``
+``PUT /ssh/keys/{id}``
+  Change a key in the authorized_keys file
+
+  Post data: ``{"ssh-key": ssh-key}``
+``DELETE /ssh/keys/{key}``
+  Delete the key with id {key} from the autorized_keys file
+