Added type definitions.

index.d.ts

@@ -0,0 +1,23 @@
+export type WarmerConfig = {
+  flag: string,
+  concurrency: string,
+  test: string,
+  log: boolean,
+  correlationId: string,
+  delay: number,
+};
+
+/**
+ * Returns a Promise that resolves to true if the current invocation is a warming
+ * invocation and false otherwise.  If this is a warming invocation, the Promise will
+ * wait until the delay specified by `config.delay` has passed.
+ *
+ * @param event the event passed to the lambda
+ * @param [config] the config options to change lambda warmer's default behavior.  All of
+ * the settings are optional
+ *
+ * @returns a Promise that resolves to true if this is a warming invocation
+ */
+function warmer(event: any, config?: WarmerConfig): Promise<boolean>;
+
+export = warmer;