updating meta tags

vacs-map-app/index.html

@@ -7,6 +7,7 @@
     <title>VACS Explorer</title>
     <meta name="title" property="og:title" content="VACS Explorer">
     <meta property="og:type" content="website">
+    <meta property="og:url" content="https://vacs.theplotline.org/#/">
     <meta name="image" property="og:image" content="https://plotine-vacs.s3.us-east-2.amazonaws.com/vacs-social.png">
     <meta name="description" property="og:description" content="Vision for Adapted Crops and Soils (VACS) addresses food security in Africa by mobilizing investment in resilient, nutritious indigenous crops suited to the changing climate. Explore the vision for yourself in this interactive application.">
   </head>