Use WebP for madamiru and sniffnet

Author: hecrj

static/showcase/madamiru.gif

@@ -136,14 +136,14 @@ <h1><a href="#showcase" class="secondary">#</a> Showcase</h1>
                 "name": "Sniffnet",
                 "description": "A network monitoring tool to help you easily keep track of your Internet traffic.",
                 "website": "https://sniffnet.net/",
-                "thumbnail": "showcase/sniffnet.png",
+                "thumbnail": "showcase/sniffnet.webp",
                 "has_webp": false,
             },
             {
                 "name": "Madamiru",
                 "description": "A media player that can dynamically shuffle multiple media in a grid layout.",
                 "website": "https://github.com/mtkennerly/madamiru",
-                "thumbnail": "showcase/madamiru.gif",
+                "thumbnail": "showcase/madamiru.webp",
                 "has_webp": false,
             },
             {