QOL: Move source code under the src directory. (#1318)

src/youtube-music.d.ts

@@ -0,0 +1,37 @@
+declare module '*.html' {
+  const html: string;
+
+  export default html;
+}
+declare module '*.svg' {
+  const element: SVGAElement;
+
+  export default element;
+}
+declare module '*.png' {
+  const element: HTMLImageElement;
+
+  export default element;
+}
+declare module '*.jpg' {
+  const element: HTMLImageElement;
+
+  export default element;
+}
+declare module '*.css' {
+  const css: string;
+
+  export default css;
+}
+
+declare module 'rollup-plugin-string' {
+  import type { Plugin } from 'rollup';
+
+  interface PluginOptions {
+    include?: string[] | string;
+    exclude?: string[] | string;
+    minifier?: unknown;
+  }
+
+  export function string(options?: PluginOptions): Plugin;
+}