fix(types): add better type for init (#376)

src/distro.ts

@@ -10,11 +10,12 @@
  * with `undefined` as value; the promise is resolved, instead of rejected, to avoid UnhandledPromiseRejectionWarning
  * or errors affecting processes using unsupported Node.js versions.
  */
+import type { LumigoSdkInitialization } from './bootstrap';
 import { LUMIGO_LOGGING_NAMESPACE } from './constants';
 import { minMajor, maxMajor } from './supportedVersions.json';
 export type { LumigoSdkInitialization } from './bootstrap';
 
-export const init = (() => {
+export const init: Promise<LumigoSdkInitialization | undefined> = (() => {
   const version = process.version;
   try {
     const nodeJsMajorVersion = parseInt(version.match(/v(\d+)\..*/)[1]);