changed inline assist generate prompt to leverage outline as opposed to entire prior file

Co-Authored-by: Antonio <antonio@zed.dev>

crates/assistant/src/assistant.rs

@@ -1,6 +1,7 @@
 pub mod assistant_panel;
 mod assistant_settings;
 mod codegen;
+mod prompts;
 mod streaming_diff;
 
 use ai::completion::Role;