Add support for extras, conditionally displaying commands in the help command, and start working on moderation commands

src/framework/commands/extras.rs

@@ -0,0 +1,32 @@
+use std::error::Error;
+
+use async_trait::async_trait;
+use twilight_model::user::User;
+
+use crate::framework::runtime::Runtime;
+
+#[async_trait]
+pub trait ExtrasGetter<S>: Send + Sync {
+    type Extras;
+
+    async fn get_extra(
+        &self,
+        user: &User,
+        rt: &Runtime<S, Self::Extras>,
+    ) -> Result<Self::Extras, Box<dyn Error>>;
+}
+
+pub struct DefaultExtraGetter;
+
+#[async_trait]
+impl<S> ExtrasGetter<S> for DefaultExtraGetter {
+    type Extras = ();
+
+    async fn get_extra(
+        &self,
+        _user: &User,
+        _rt: &Runtime<S, Self::Extras>,
+    ) -> Result<Self::Extras, Box<dyn Error>> {
+        Ok(())
+    }
+}