feat: update implementation of RSS feeds

Adds a new filter `convertRelativeLinks` that converts any relative link
to an absolute path
Adds an XML transform to minify the final output for smaller filesizes
Updates some data in meta
Adds a new macro for generating an RSS feed

src/data/meta.js

@@ -1,6 +1,6 @@
 export default {
   url: process.env.URL || "http://localhost:8080",
-  siteName: "wonderfulfrog",
+  siteName: "wonderfulfrog.com",
   siteDescription:
     "My name is Devin Haska and this is my little slice of the internet I call home.",
   locale: "en_EN",