docs: update linux run

add note about libclang on linux

README.md

@@ -6,8 +6,8 @@
 1. Install rust
 1. Install ffmpeg 7.*, sdl2, sdl2_mixer, sdl2_image, sdl2_ttf.
     - For instructions on sdl2 installation, see [rust-sdl2 README](https://github.com/Rust-SDL2/rust-sdl2).
-    - You may have to install libclang on some platforms (e.g. Raspberry Pi)
 1. Run `cargo build`
+    - If there's an error related to FFmpeg library building, try installing EVERY libraries related to libclang, INCLUDING development libraries. this may fix the problem.
 1. When running the game, `assets` directory and `music` directory should be in the working directory.
 
 ### Mac OS
@@ -73,4 +73,4 @@ This program, including source code, cannot be used/copied/redistributed/modifie
  - Noto Sans KR: Copyright (C) Google, licensed under SIL Open Font License
  - [Press Start](https://www.fontspace.com/press-start-2p-font-f11591): Copyright (c) 2011, Cody "CodeMan38" Boisclair (cody@zone38.net), licensed under SIL Open Font License (OFL)
  - Janggu free icon: [Korea icons created by Freepik - Flaticon](https://www.flaticon.com/free-icons/korea)
- - Title background video: [Seoul Korea - Free Paper Style Background Loop](https://www.youtube.com/watch?v=6G_v0eLtbRE)
+ - Title background video: [Seoul Korea - Free Paper Style Background Loop](https://www.youtube.com/watch?v=6G_v0eLtbRE)