Fix rotation (ShizukuIchi#14)

fix pdfs with origin rotation other than 0

Author: ShizukuIchi

src/PDFPage.svelte

@@ -15,7 +15,7 @@
   async function render() {
     const _page = await page;
     const context = canvas.getContext("2d");
-    const viewport = _page.getViewport({ scale: 1 });
+    const viewport = _page.getViewport({ scale: 1, rotation: 0 });
     width = viewport.width;
     height = viewport.height;
     await _page.render({