[doc] Update developing plan

README.md

@@ -16,5 +16,6 @@ A Golang library to make development easier and more efficient
 
 1. Robustness: Add fuzz tests to ensure the robustness of the library.
 2. Maintainability: Add annotations to the code to make it more readable; standardize the naming of the functions and variables to make it more consistent.
-3. Provide more practical functions in `functools` for manipulating `sequences` (`slice`/`array`/`string`).
-4. Generate documentation for the library and provide examples for each function.
+3. Functionality: Provide more practical functions in `functools` for manipulating `sequences` (`slice`/`array`/`string`).
+4. Usability: Generate documentation for the library and provide examples for each function.
+5. Compatibility: Support lower versions of `Golang` to ensure compatibility with older projects; split `typed` package.