Fix: Volume scrolling (LNReader#1114)

* Volume scrolling fix

the scrolling by volume button right now scrolls 100% of the screen, which hides text when scrolled so, the commit is just changing the the scrolling to 50%.

* typo

* 50% to 75% scroll

---------

Co-authored-by: Ridi <ridi.culous.progger@gmail.com>

src/screens/reader/ReaderScreen.tsx

@@ -132,15 +132,16 @@ export const ChapterContent = ({
     VolumeButtonListener.preventDefault();
     emmiter.current.addListener('VolumeUp', () => {
       webViewRef.current?.injectJavaScript(`(()=>{
-          window.scrollBy({top:${-Dimensions.get('window')
-            .height},behavior:'smooth',})
+          window.scrollBy({top: -${
+            Dimensions.get('window').height * 0.75
+          }, behavior: 'smooth'})
         })()`);
     });
     emmiter.current.addListener('VolumeDown', () => {
       webViewRef.current?.injectJavaScript(`(()=>{
-          window.scrollBy({top:${
-            Dimensions.get('window').height
-          },behavior:'smooth',})
+          window.scrollBy({top: ${
+            Dimensions.get('window').height * 0.75
+          }, behavior: 'smooth'})
         })()`);
     });
   };