Add TypeScript declarations for the existing public surface

.eslintignore

@@ -1 +1,4 @@
 **/*{.,-}min.js
+types-test.ts
+tsconfig.types.json
+*.d.ts

.github/workflows/lint.yml

@@ -13,3 +13,13 @@ jobs:
         node-version: "16"
     - run: npm install
     - run: npm run lint
+
+  types:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-node@v4
+      with:
+        node-version: "22"
+    - run: npm install
+    - run: npm run test:types

.npmignore

@@ -20,4 +20,6 @@ Makefile
 tests
 .travis*
 *.tgz
-*.md
+*.md
+types-test.ts
+tsconfig.types.json

README.md

@@ -47,6 +47,21 @@ In order to manage the lifetime of your access token and minimize the number of
 
 As calls are asynchronous, use `await` when executing API calls, otherwise the calls will not use the cached token.
 
+### TypeScript
+
+Type declarations ship with the package. There is no separate `@types` package to install.
+
+```typescript
+import api from "gettyimages-api";
+
+const client = new api({ apiKey: "your_api_key", apiSecret: "your_api_secret" });
+const response = await client.searchimages().withPhrase("beach").withPageSize(1).execute();
+```
+
+Builders named in the singular, such as `withCollectionCode`, accept either a single value or
+an array of values. Responses are typed as `any`, because the API returns different fields
+depending on the endpoint, the requested response fields, and your products.
+
 ## Examples
 
 Ensure that `"type": "module"` is set in your `package.json` to enable ES Modules and async/await support.