Apply suggestions from code review

Co-authored-by: James Sumners <321201+jsumners@users.noreply.github.com>
Signed-off-by: Matteo Collina <matteo.collina@gmail.com>

fastify.js

@@ -2,7 +2,6 @@
 
 const VERSION = '5.0.0-alpha.1'
 
-
 const Avvio = require('avvio')
 const http = require('node:http')
 let lightMyRequest

lib/server.js

@@ -297,7 +297,19 @@ function getServerInstance (options, httpHandler) {
   }
   return server
 }
-
+/**
+ * Inspects the provided `server.address` object and returns a
+ * normalized list of IP address strings. Normalization in this
+ * case refers to mapping wildcard `0.0.0.0` to the list of IP
+ * addresses the wildcard refers to.
+ *
+ * @see https://nodejs.org/docs/latest/api/net.html#serveraddress
+ *
+ * @param {object} A server address object as described in the
+ * linked docs.
+ *
+ * @returns {string[]}
+ */
 function getAddresses (address) {
   if (address.address === '0.0.0.0') {
     return Object.values(os.networkInterfaces()).flatMap((iface) => {