docs: update links alignment

Author: husa

README.md

@@ -1,8 +1,8 @@
 <p align="center">
   <a href="https://chrome.google.com/webstore/detail/e-clock/ojhhcfhabhligodffabdhcaoicecaboo">
-    <img src="https://developer.chrome.com/static/docs/webstore/branding/image/HRs9MPufa1J1h5glNhut.png" alt="e-clock" aria-label="e-clock" />
-  </a>
+    <img src="https://developer.chrome.com/static/docs/webstore/branding/image/HRs9MPufa1J1h5glNhut.png" alt="e-clock" aria-label="e-clock" width="248"/></a>
+</p>
+<p align="center">
   <a href="https://addons.mozilla.org/firefox/addon/eclock/">
-    <img src="https://blog.mozilla.org/addons/files/2020/04/get-the-addon-fx-apr-2020.svg" alt="e-clock" aria-label="e-clock" width="496px"/>
-  </a>  
+    <img src="https://blog.mozilla.org/addons/files/2020/04/get-the-addon-fx-apr-2020.svg" alt="e-clock" aria-label="e-clock" width="248"/></a>  
 </p>