Add Castbox (#2715)

_data/simple-icons.json

@@ -820,6 +820,11 @@
             "hex": "1287B1",
             "source": "https://upload.wikimedia.org/wikipedia/commons/5/5e/Cassandra_logo.svg"
         },
+        {
+            "title": "Castbox",
+            "hex": "F55B23",
+            "source": "https://castbox.fm/newsroom/"
+        },
         {
             "title": "Castorama",
             "hex": "0078D7",

icons/castbox.svg

@@ -0,0 +1 @@
+<svg role="img" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>Castbox icon</title><path d="M12 0c-.29 0-.58.068-.812.206L2.417 5.392c-.46.272-.804.875-.804 1.408v10.4c0 .533.344 1.135.804 1.407l8.77 5.187c.465.275 1.162.275 1.626 0l8.77-5.187c.46-.272.804-.874.804-1.407V6.8c0-.533-.344-1.136-.804-1.408L12.813.206A1.618 1.618 0 0012 0zm-.85 8.304c.394 0 .714.303.714.676v2.224c0 .207.191.375.427.375s.428-.168.428-.375V9.57c0-.373.32-.675.713-.675.394 0 .712.302.712.675v4.713c0 .374-.318.676-.712.676-.394 0-.713-.302-.713-.676v-1.31c0-.206-.192-.374-.428-.374s-.427.168-.427.374v1.226c0 .374-.32.676-.713.676-.394 0-.713-.302-.713-.676v-1.667c0-.207-.192-.375-.428-.375-.235 0-.427.168-.427.375v3.31c0 .373-.319.676-.712.676-.394 0-.713-.303-.713-.676v-2.427c0-.206-.191-.374-.428-.374-.235 0-.427.168-.427.374v.178a.71.71 0 01-.712.708.71.71 0 01-.713-.708v-2.123a.71.71 0 01.713-.708.71.71 0 01.712.708v.178c0 .206.192.373.427.373.237 0 .428-.167.428-.373v-1.53c0-.374.32-.676.713-.676.393 0 .712.303.712.676v.646c0 .206.192.374.427.374.236 0 .428-.168.428-.374V8.98c0-.373.319-.676.713-.676zm4.562 2.416c.393 0 .713.302.713.676v2.691c0 .374-.32.676-.713.676-.394 0-.712-.303-.712-.676v-2.691c0-.374.319-.676.712-.676zm2.28 1.368c.395 0 .713.303.713.676v.67c0 .374-.318.676-.712.676-.394 0-.713-.302-.713-.675v-.67c0-.374.32-.677.713-.677Z"/></svg>