Add declaration maps

Author: wooorm

.gitignore

@@ -1,6 +1,7 @@
 .DS_Store
 *.d.ts
 *.log
+*.map
 *.tsbuildinfo
 coverage/
 node_modules/

package.json

@@ -39,6 +39,7 @@
   "types": "index.d.ts",
   "files": [
     "lib/",
+    "index.d.ts.map",
     "index.d.ts",
     "index.js"
   ],

tsconfig.json

@@ -2,6 +2,7 @@
   "compilerOptions": {
     "checkJs": true,
     "customConditions": ["development"],
+    "declarationMap": true,
     "declaration": true,
     "emitDeclarationOnly": true,
     "exactOptionalPropertyTypes": true,