type: Add type file.

main.d.ts

@@ -0,0 +1,24 @@
+
+export type ColorScheme = 'light' | 'dark';
+export type ColorSchemeChangeEvent = CustomEvent<{ colorScheme: ColorScheme }>;
+export class DarkMode extends HTMLElement {
+  mode?: ColorScheme;
+  dark?: string;
+  light?: string;
+  style?: React.CSSProperties;
+}
+
+declare global {
+  interface HTMLElementTagNameMap {
+    'dark-mode': DarkMode;
+  }
+  interface GlobalEventHandlersEventMap {
+    'colorschemechange': ColorSchemeChangeEvent;
+  }
+}
+
+declare namespace JSX {
+  interface IntrinsicElements {
+    'dark-mode': DarkMode;
+  }
+}

package.json

@@ -7,6 +7,7 @@
   "module": "./dist/dark-mode.min.js",
   "exports": "./dist/dark-mode.min.js",
   "unpkg": "./dist/dark-mode.min.js",
+  "types": "./main.d.ts",
   "scripts": {
     "clean": "shx rm -rf ./dist && mkdir dist",
     "build": "npm run clean && npx terser ./main.js --toplevel --mangle-props regex=\\\"^_\\\" --comments /@license/ --ecma=8 -o ./dist/dark-mode.min.js"