Add more doc

src/entity/active_model.rs

@@ -243,6 +243,7 @@ where
     exec.await
 }
 
+/// Delete an active model by its primary key
 pub async fn delete_active_model<A, E>(
     mut am: A,
     db: &DatabaseConnection,

src/entity/column.rs

@@ -66,6 +66,7 @@ macro_rules! bind_vec_func {
 }
 
 // LINT: when the operand value does not match column type
+/// Wrapper of the identically named method in [`sea_query::Expr`]
 pub trait ColumnTrait: IdenStatic + Iterable {
     type EntityName: EntityName;