Add TypeScript declaration maps

Closes GH-230.

Reviewed-by: Christian Murphy <[email protected]>
Reviewed-by: Titus Wormer <[email protected]>

Author: remcohaszing

.gitignore

@@ -3,6 +3,7 @@ node_modules/
 .DS_Store
 *.d.ts
 *.log
+*.map
 yarn.lock
 !/index.d.ts
 !/test/types.d.ts

tsconfig.json

@@ -3,6 +3,7 @@
     "checkJs": true,
     "customConditions": ["development"],
     "declaration": true,
+    "declarationMap": true,
     "emitDeclarationOnly": true,
     "exactOptionalPropertyTypes": true,
     "lib": ["es2022"],