Merge pull request #84 from snikket-im/docs/add-user-roles-page

docs: Add page about user roles

docs/features/user_roles.md

@@ -0,0 +1,53 @@
+---
+title: User roles
+---
+
+# User roles
+
+Snikket allows you to select a role for users, each role granting different
+permissions.
+
+Each user may have one of three roles:
+
+## Administrator
+
+This is the default role of the first user (if you're reading this, that's
+probably you!).
+
+Administrators have full control over the server, settings, users and circles.
+These features can be accessed primarily through the admin panel in the
+Snikket web interface.
+
+## Normal
+
+This is the default role for most users. It gives access to all
+non-administrative server functionality.
+
+## Limited
+
+Limited users have various restrictions. The purpose of this role is to
+allow granting someone an account on the server, only for the purposes of
+communicating with other people on that server. This can be useful to provide
+a guest or child account, for example.
+
+In particular, limited users are not allowed to:
+
+- Communicate with users on other servers
+- Join group chats on other servers
+- Create public channels (including on the current server)
+- Invite new users to the server (regardless of whether this is enabled for
+  normal users).
+
+### Caveats
+
+The current support for limited users has some known issues. It is designed to
+prevent casual misuse of the server, but it is not intended to be a foolproof
+security measure. For example, limited users are still able to *receive*
+messages and contact requests from other servers, even though they cannot send
+them to other servers. It is expected that we will restrict incoming traffic
+for limited users in a future release, after further testing.
+
+Also note that limited accounts may have issues using non-Snikket mobile apps
+that use push notifications, depending on the design of the app. This is
+because the restrictions may prevent the app communicating with its'
+developer's push notification services over XMPP.