Merge branch 'feature/digest-email' into 'develop'

Feature/digest email

See merge request pleroma/pleroma!1078

docs/config.md

@@ -536,6 +536,18 @@ Authentication / authorization settings.
 * `oauth_consumer_template`: OAuth consumer mode authentication form template. By default it's `consumer.html` which corresponds to `lib/pleroma/web/templates/o_auth/o_auth/consumer.html.eex`.
 * `oauth_consumer_strategies`: the list of enabled OAuth consumer strategies; by default it's set by `OAUTH_CONSUMER_STRATEGIES` environment variable. Each entry in this space-delimited string should be of format `<strategy>` or `<strategy>:<dependency>` (e.g. `twitter` or `keycloak:ueberauth_keycloak_strategy` in case dependency is named differently than `ueberauth_<strategy>`).
 
+## :email_notifications
+
+Email notifications settings.
+
+  - digest - emails of "what you've missed" for users who have been
+    inactive for a while.
+    - active: globally enable or disable digest emails
+    - schedule: When to send digest email, in [crontab format](https://en.wikipedia.org/wiki/Cron).
+      "0 0 * * 0" is the default, meaning "once a week at midnight on Sunday morning"
+    - interval: Minimum interval between digest emails to one user
+    - inactivity_threshold: Minimum user inactivity threshold
+
 ## OAuth consumer mode
 
 OAuth consumer mode allows sign in / sign up via external OAuth providers (e.g. Twitter, Facebook, Google, Microsoft, etc.).