feat: switch to remark from markdown-it (big)

* replaces old mentions with avatar and display name
* renders things directly through React
* replaces most of the markdown hacks with custom AST components
* adds a tooltip to codeblock "copy to clipboard"

src/components/markdown/plugins/anchors.tsx

@@ -0,0 +1,34 @@
+import { Link } from "react-router-dom";
+
+import { determineLink } from "../../../lib/links";
+
+import { modalController } from "../../../controllers/modals/ModalController";
+
+export function RenderAnchor({
+    href,
+    ...props
+}: JSX.HTMLAttributes<HTMLAnchorElement>) {
+    // Pass-through no href or if anchor
+    if (!href || href.startsWith("#")) return <a href={href} {...props} />;
+
+    // Determine type of link
+    const link = determineLink(href);
+    if (link.type === "none") return <a {...props} />;
+
+    // Render direct link if internal
+    if (link.type === "navigate") {
+        return <Link to={href} children={props.children} />;
+    }
+
+    return (
+        <a
+            {...props}
+            href={href}
+            target="_blank"
+            rel="noreferrer"
+            onClick={(ev) =>
+                modalController.openLink(href) && ev.preventDefault()
+            }
+        />
+    );
+}