chore: update v0.45.0 removal notice (#1687)

* chore: update deprecation notice

* Add deprecation page to sidebar

* Replace the use of "deprected" with "removed"

src/config.rs

@@ -20,6 +20,9 @@ where
     /// Load root module config from given Value and fill unset variables with default
     /// values.
     fn load(config: &'a Value) -> Self {
+        if config.get("prompt_order").is_some() {
+            log::warn!("\"prompt_order\" has been removed in favor of \"format\". For more details, see: https://starship.rs/migrating-to-0.45.0/")
+        }
         Self::new().load_config(config)
     }