add a list of planned features and development ideas

- TODO: setup an issue tracker

docs/ideas.rst

@@ -0,0 +1,19 @@
+Development ideas and planned features
+======================================
+
+* password reset for
+
+  - OS users
+  - mailboxes
+
+* add ssh key management for sftp users
+
+* link to phpmyadmin and phppgadmin
+
+* link to webmail
+
+* list mail domains
+
+* CRUD for mailboxes
+
+* CRUD for mail addresses

docs/index.rst

@@ -25,6 +25,7 @@ Contents:
    deploy
    tests
    code
+   ideas
    changelog