fix: error happens when parsing readme content (#1873)

frontend/rust-lib/flowy-document/src/editor/mod.rs

@@ -9,8 +9,8 @@ pub use document_serde::*;
 pub use editor::*;
 
 #[inline]
+// Return the read me document content
 pub fn initial_read_me() -> String {
   let document_content = include_str!("READ_ME.json");
-  let transaction = make_transaction_from_document_content(document_content).unwrap();
-  transaction.to_json().unwrap()
+  return document_content.to_string();
 }