Add nginx.conf

Add nginx configuration example for rewrite rules.

Closes #12.

nginx.conf

@@ -0,0 +1,27 @@
+server {
+
+  # Match this with your setup
+  listen 80;
+  server_name _;
+
+  root /var/www/html;
+  index index.php;
+
+  # START rewrite rules
+  location /shorten {
+    try_files $uri $uri/ /shorten.php?$args;
+  }
+
+  location / {
+    rewrite ^/(.*)$ /index.php?slug=$1 last;
+    try_files $uri $uri/ /index.php;
+  }
+  # END rewrite rules
+
+  # Match this with your setup
+  location ~ \.php$ {
+    include snippets/fastcgi-php.conf;
+    fastcgi_pass unix:/run/php/php7.0-fpm.sock;
+  }
+
+}