Adding myself to maintainers list (#433)

config/maintainers.json

@@ -60,6 +60,16 @@
       "link_url": "https://www.sborza.com/",
       "avatar_url": null,
       "bio": "I'm a Canadian (based in Chicago) golang, C and python developer working on projects within the gaming, finance and data-science worlds respectively. My favorite freetime task is coding challenges and I'm more than happy to help people talk through solutions!"
+    },
+    {
+      "github_username": "ondono",
+      "alumnus": false,
+      "show_on_website": false,
+      "name": "Xavi Ondoño",
+      "link_text": "xaviondono.com",
+      "link_url": "https://www.xaviondono.com/",
+      "avatar_url": null,
+      "bio": "I'm a catalan hardware designer and firmware developer working on ARM and x64 architectures."
     }
   ]
 }