Update OG image urls

Author: Salma Alam-Naylor

apps/fretonator-web/src/index.html

@@ -10,14 +10,14 @@
   <meta property="og:description"
         content="Choose a starting note, pick a mode, check out the fretboard and have a jam!"/>
   <meta property="og:url" content="https://www.fretonator.com"/>
-  <meta property="og:image" content="https://fretonator.netlify.app/assets/img/og_facebook.png"/>
+  <meta property="og:image" content="https://www.fretonator.com/assets/img/og_facebook.png"/>
   <meta property="og:image:alt" content="Fretonator - the ultimate free guitar theory tool"/>
   <meta property="og:image:width" content="1200"/>
   <meta property="og:image:height" content="630"/>
   <meta property="og:image:type" content="image/png"/>
 
   <meta name="twitter:card" content="summary_large_image"/>
-  <meta name="twitter:image" content="https://fretonator.netlify.app/assets/img/og_twitter.png"/>
+  <meta name="twitter:image" content="https://www.fretonator.com/assets/img/og_twitter.png"/>
   <meta name="twitter:image:alt" content="Fretonator - the ultimate free guitar theory tool"/>
   <meta name="twitter:description"
         content="Choose a starting note, pick a mode, check out the fretboard and have a jam!"/>