[joox] docs #1: improve joox method docs

um_wasm/src/exports/joox.rs

@@ -16,11 +16,14 @@ impl JsJooxFile {
         ))
     }
 
+    /// Get the buffer size to allocate for decrypt method.
     #[wasm_bindgen(getter, js_name = "bufferLength")]
     pub fn get_buffer_size(&self) -> usize {
         self.0.get_audio_block_size()
     }
 
+    /// Decrypt a given block of buffer (see {@link bufferLength})
+    /// Return the length of decrypted & unpadded data from the input buffer.
     #[wasm_bindgen(js_name = "decrypt")]
     pub fn decrypt(&self, buffer: &mut [u8]) -> Result<usize, JsError> {
         let decrypted = self.0.decrypt_audio_block(buffer).map_err(JsError::from)?;