flesh out features

Signed-off-by: cinereal <cinereal@riseup.net>

architecture-docs/architecture.md

@@ -114,9 +114,39 @@ Primary platform features toward operators will include:
 1. install selected applications
 1. configure applications
 1. update applications
-1. switch to a different host (service portability)
+1. switch to a different host
 1. user management
 
+### Install selected applications
+
+Operators should be able to easily select desired applications to install (i.e. deploy), ideally in bulk.
+Selected applications will be deployed to the operator's own domain.
+The operator will be notified how to access their applications, once these are ready to use.
+
+### Configure applications
+
+Applications may be complex enough to warrant not using a one-size-fits-all approach.
+As such, relevant configuration options should be made available for operators to tweak.
+Nevertheless, we should default to a batteries-included approach, applying sane defaults such that only power users should need to access any advanced settings.
+
+### Update applications
+
+Updates are relevant not only for new features, but for security purposes as well.
+As such, hosting providers should be able to present operators with options on updating policy, which may include updating when possible, notifying the operator on (major/minor) updates, or applying application-specific preferences.
+Application state should be backed up prior to updates, and users should be guided through relevant new configuration options, if desired.
+
+### Switch to a different host
+
+In the event an operator would like to take their applications to a different hosting company, they may make use of our service portability feature.
+This allows an operator to get a token that allows access to their deployment state, which may they may enter at their new host to transfer their applications while importing any relevant application data.
+In case the web hosts do not run exactly the same versions of Fediversity, such migrations should nevertheless be gracefully handled, within reasonable bounds.
+
+### User management
+
+Operators may expect their applications are usable to others they want to make accounts for, so that they may use the applications to collaborate.
+To make this possible, we will offer a web interface to let them manage users and associated rights (utilizing standards such as LDAP).
+Single sign-on (SSO) will be offered to facilitate a unified log-in experience across deployed applications, including support for relevant security measures like multi-factor authentication (MFA).
+
 ## Architecture
 
 At the core of Fediversity lies a NixOS configuration module for a set of selected applications.