New pattern for comment creation in code

Use the builder design pattern to build a NewComment

Add a function to transform a NewComment into a Create activity

Virtually send this activity to the shared inbox of the instance

src/main.rs

@@ -71,6 +71,7 @@ fn main() {
             routes::comments::new,
             routes::comments::new_auth,
             routes::comments::create,
+            routes::comments::create_response,
 
             routes::instance::index,
             routes::instance::shared_inbox,