add: option to hide posts answering questions from "All" timeline

crates/core/src/model/auth.rs

@@ -240,6 +240,9 @@ pub struct UserSettings {
     /// Automatically unlist posts from timelines.
     #[serde(default)]
     pub auto_unlist: bool,
+    /// Hide posts that are answering a question on the "All" timeline.
+    #[serde(default)]
+    pub all_timeline_hide_answers: bool,
 }
 
 fn mime_avif() -> String {