fix: re-add interfaces (#218)

Signed-off-by: Grant Timmerman <timmerman+devrel@google.com>

Author: grant

package.json

@@ -7,7 +7,7 @@
  },
  "repository": "GoogleCloudPlatform/functions-framework-nodejs",
  "main": "build/src/index.js",
- "types": "build/src/invoker.d.ts",
+ "types": "build/src/functions.d.ts",
  "dependencies": {
  "body-parser": "^1.18.3",
  "express": "^4.16.4",

src/functions.ts

@@ -12,6 +12,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+// Type Interfaces for the Node Functions Framework.
+// **If changing files, please change package.json!**
+
 /* eslint-disable @typescript-eslint/no-explicit-any */
 import * as express from 'express';