Document EntityCommands/EntityMut insert() (#6270)

Fixes #6258.

Author: JMS55

crates/bevy_ecs/src/system/commands/mod.rs

@@ -321,7 +321,7 @@ impl<'w, 's> Commands<'w, 's> {
     ///     if let Some(mut entity_commands) = commands.get_entity(entity) {
     ///         // adds a single component to the entity
     ///         entity_commands.insert(Label("hello world"));
-    ///     }      
+    ///     }
     /// }
     /// # bevy_ecs::system::assert_is_system(example_system);
     /// ```
@@ -565,6 +565,8 @@ impl<'w, 's, 'a> EntityCommands<'w, 's, 'a> {
 
     /// Adds a [`Bundle`] of components to the entity.
     ///
+    /// This will overwrite any previous value(s) of the same component type.
+    ///
     /// # Panics
     ///
     /// The command will panic when applied if the associated entity does not exist.

crates/bevy_ecs/src/world/entity_ref.rs

@@ -246,6 +246,9 @@ impl<'w> EntityMut<'w> {
         self.insert(bundle)
     }
 
+    /// Adds a [`Bundle`] of components to the entity.
+    ///
+    /// This will overwrite any previous value(s) of the same component type.
     pub fn insert<T: Bundle>(&mut self, bundle: T) -> &mut Self {
         let change_tick = self.world.change_tick();
         let bundle_info = self