chore: add TypeScript config to generate definition

package.json

@@ -34,7 +34,7 @@
 	},
 	"scripts": {
 		"changelog": "conventional-changelog -p @commitlint/config-conventional -s -i CHANGELOG.md && prettier CHANGELOG.md --write",
-		"doc": "jsdoc2md src/index.js > API.md && prettier API.md --write",
+		"doc": "tsc && jsdoc2md src/index.js > API.md && prettier API.md --write",
 		"dupe-check": "yarn jsinspect ./src",
 		"lint": "eslint . --cache --ext js,jsx,ts,tsx --ignore-path .gitignore",
 		"prettier": "prettier . --write --ignore-path .gitignore",
@@ -75,6 +75,7 @@
 		"jest": "^26.5.3",
 		"jsdoc-to-markdown": "^6.0.1",
 		"jsinspect": "^0.12.7",
-		"prettier": "2.1.2"
+		"prettier": "2.1.2",
+		"typescript": "^4.0.3"
 	}
 }

tsconfig.json

@@ -0,0 +1,8 @@
+{
+	"include": ["src/index.js"],
+	"compilerOptions": {
+		"declaration": true,
+		"emitDeclarationOnly": true,
+		"allowJs": true
+	}
+}

yarn.lock

@@ -5581,6 +5581,11 @@ typedarray-to-buffer@^3.1.5:
   dependencies:
     is-typedarray "^1.0.0"
 
+typescript@^4.0.3:
+  version "4.0.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.0.3.tgz#153bbd468ef07725c1df9c77e8b453f8d36abba5"
+  integrity sha512-tEu6DGxGgRJPb/mVPIZ48e69xCn2yRmCgYmDugAVwmJ6o+0u1RI18eO7E7WBTLYLaEVVOhwQmcdhQHweux/WPg==
+
 typical@^2.4.2, typical@^2.6.0, typical@^2.6.1:
   version "2.6.1"
   resolved "https://registry.yarnpkg.com/typical/-/typical-2.6.1.tgz#5c080e5d661cbbe38259d2e70a3c7253e873881d"