add script to generate Modrinth-compatible readme

.gitignore

@@ -287,3 +287,8 @@ Temporary Items
 .idea/
 
 /run/
+
+node_modules/
+package.json
+bun.lock
+README-modrinth.md

readme-modrinth.ts

@@ -0,0 +1,37 @@
+#!/usr/bin/env bun
+
+// readme-modrinth.ts
+//  Generates a version of README.md that is suitable for use as
+//  the plugin description on Modrinth.
+//
+// For this file to work smoothly in your editor, please run:
+//  bun add --dev @types/bun
+// The files generated by this command are included in the gitignore.
+
+const BASE_RAW_URL =
+    // trailing slash is important!
+    // otherwise, URL constructor treats `main` as a file, not a directory path
+    "https://raw.githubusercontent.com/ModernBetaNetwork/AdminToolbox/refs/heads/main/";
+
+const readme = Bun.file("README.md");
+const modrinthReadme = Bun.file("README-modrinth.md");
+let text = await readme.text();
+
+// remove first h1
+text = text.replace(/^(# .+\n+)/, "");
+
+// replace all repo images with GitHub raw url
+text = text.replaceAll(/!\[(.*?)\]\((.*?)\)/g, (_, alt, url) => {
+    if (url.startsWith("./")) {
+        return `![${alt}](${new URL(url, BASE_RAW_URL).href})`;
+    }
+    return `![${alt}](${url})`;
+});
+
+// remove all heading links, modrinth doesn't support them
+text = text.replaceAll(/\[(.*?)\]\(#.*\)/g, (_, text) => text);
+
+// save modrinth readme output
+modrinthReadme.write(text);
+
+export {};