Refactor to simplify TypeScript build

Closes GH-83.

Reviewed-by: Christian Murphy <christian.murphy.42@gmail.com>
Reviewed-by: Titus Wormer <tituswormer@gmail.com>

package.json

@@ -70,7 +70,7 @@
   },
   "scripts": {
     "prepack": "npm run build && npm run format",
-    "build": "rimraf \"lib/**/*.d.ts\" \"test.d.ts\" && tsc && tsc --noEmit index.d.ts && type-coverage",
+    "build": "tsc --build --clean && tsc --build && type-coverage",
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
     "test-api": "node test.js",
     "test-coverage": "c8 --check-coverage --branches 100 --functions 100 --lines 100 --statements 100 --reporter lcov node test.js",

tsconfig.json

@@ -1,10 +1,10 @@
 {
-  "include": ["lib/**/*.js", "test.js"],
+  "include": ["**/*.js", "index.d.ts"],
+  "exclude": ["coverage", "node_modules"],
   "compilerOptions": {
     "target": "ES2020",
     "lib": ["ES2020"],
-    "module": "ES2020",
-    "moduleResolution": "node",
+    "module": "Node16",
     "allowJs": true,
     "checkJs": true,
     "declaration": true,