Update README.md

[Github Releases](https://github.com/JavaCafe01/PdfViewer/releases)

<a href='https://play.google.com/store/apps/details?id=com.gsnathan.pdfviewer'><img width="250" alt='Get it on Google Play' src='https://play.google.com/intl/en_us/badges/images/generic/en_badge_web_generic.png'/></a>

<a href="https://play.google.com/store/apps/details?id=com.gsnathan.pdfviewer">

    <img alt="Get it on Google Play"

        height="80"

        src="https://play.google.com/intl/en_us/badges/images/generic/en_badge_web_generic.png" />

</a>

## Screenshots

| Main Page | Settings Page |

|:-:|:-:|

| <img src ="./images/mainpage.png" width="190" height="360"/> | <img src ="./images/mainpage2.png" width="190" height="360"/> |

| <img src ="./images/mainpage.png" width="190" height="340"/> | <img src ="./images/mainpage2.png" width="190" height="340"/> |

| [`MainActivity.java`](https://github.com/JavaCafe01/PdfViewer/blob/master/app/src/main/java/com/gsnathan/pdfviewer/MainActivity.java) |  [`MainActivity.java`](https://github.com/JavaCafe01/PdfViewer/blob/master/app/src/main/java/com/gsnathan/pdfviewer/MainActivity.java)  |