Merge pull request 'add docs' (#1056) from docs into staging

Reviewed-on: #1056

src/model/planned/event.rs

@@ -13,6 +13,7 @@ use crate::model::{
     user::{EventUser, User},
 };
 
+/// DB structure of an event
 #[derive(Serialize, Clone, FromRow, Debug, PartialEq)]
 pub struct Event {
     pub id: i64,

src/model/planned/mod.rs

@@ -1,5 +1,19 @@
+//! This module contains everything for managing planned trips and events.
+//! `Cox` can create trips, `EventUser` can create events. Rowers can join those.
+
+/// Events can be created by everyone who has the `manage_events` role. They are used if multiple coxes are needed, e.g. for "Fetzenfahrt", "Anrudern", .... Additionally, events are shown in public calendar (e.g. on the website).
 pub mod event;
+
+/// Trips can be created by every cox. They are "simple", every-day trips.
 pub mod trip;
+
+/// Extracts the common data for both Trips and Events. Rower can register using this.
 pub mod tripdetails;
+
+/// Type of the trip
 pub mod triptype;
+
+/// Associative table between `User` and `TripDetails`. Its functionality should probably move into
+/// those files.
+// TODO: make this mod unnecessary
 pub mod usertrip;