chore(seo): add seo to index html

src/index.html

@@ -13,6 +13,13 @@
 
   <link rel="icon" type="image/png" href="assets/icon/favicon.png" />
 
+  <meta name="description" content="fivethree website">
+  <meta name="keywords" content="fivethree,bonn,köln,web app,mobile app,pwa,backend,freelancer,freiberufler,software entwickler,developers,angular,ionic,spring boot,java,typescript">
+
+  <meta property="og:type" content="website">
+  <meta property="og:title" content="fivethree">
+  <meta property="og:description" content="fivethree website">
+  <meta property="og:url" content="https://fivethree.io/">
   <!-- add to homescreen for ios -->
   <meta name="apple-mobile-web-app-capable" content="yes" />
   <meta name="apple-mobile-web-app-status-bar-style" content="black" />