Adds NGINX logo

Fix #413
Based on favicon from nginx.com
Full logo not used due to guidelines (min width 72px)
Outlined hexagon not used due to confusion with NodeJS
Color is not consistent on NGINX site

_data/simple-icons.json

@@ -900,6 +900,11 @@
             "hex": "E50914",
             "source": "https://commons.wikimedia.org/wiki/File:Netflix_2014_logo.svg"
         },
+        {
+            "title": "NGINX",
+            "hex": "269539",
+            "source": "https://www.nginx.com/"
+        },
         {
             "title": "Nintendo",
             "hex": "8F8F8F",

icons/nginx.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" version="1.2" baseProfile="tiny" viewBox="0 0 16 16"><path d="M8 0L1.07 4v8L8 16l6.93-4V4L8 0zm4 11.06c0 .47-.43.86-1.02.86-.42 0-.9-.17-1.2-.54l-4-4.76v4.44c0 .48-.38.86-.85.86h-.05c-.48 0-.86-.4-.86-.86V4.94c0-.47.42-.86 1-.86.43 0 .92.17 1.22.54l3.98 4.76V4.94c0-.48.4-.86.86-.86h.05c.48 0 .86.4.86.86v6.12z"/></svg>