Add testing-library/jest-dom types for pnpm

pnpm installs these types to node_modules/.pnpm by default, so we need
to explicitly add this dependency.

See testing-library/jest-dom#123 (comment)

README.md

@@ -20,29 +20,29 @@
 
 1. Clone this repo to your desired path:
 
-    ```sh
-    git clone git@github.com:startkit-dev/startkit-next.git my-new-project
-    ```
+   ```sh
+   git clone git@github.com:startkit-dev/startkit-next.git my-new-project
+   ```
 
 2. Rename the project:
 
-    ```sh
-    ./bin/rename
-    ```
+   ```sh
+   ./bin/rename
+   ```
 
 3. Update your git remote to point to StartKit as `upstream`
 
-    ```sh
-    git remote rename origin upstream
-    ```
+   ```sh
+   git remote rename origin upstream
+   ```
 
-    In the future, you'll be able to pull in the latest StartKit changes without
-    missing a beat by running:
+   In the future, you'll be able to pull in the latest StartKit changes without
+   missing a beat by running:
 
-    ```sh
-    git fetch upstream
-    git pull upstream/main
-    ```
+   ```sh
+   git fetch upstream
+   git pull upstream/main
+   ```
 
 ## Getting Started
 

package.json

@@ -31,6 +31,7 @@
     "@types/node": "^18.11.19",
     "@types/react": "^18.0.27",
     "@types/react-dom": "^18.0.11",
+    "@types/testing-library__jest-dom": "^5.14.5",
     "@typescript-eslint/eslint-plugin": "^5.48.0",
     "autoprefixer": "^10.4.13",
     "eslint": "^8.33.0",