docs: README update

Author: KiraLT

README.md

@@ -16,6 +16,7 @@ Download latest version of `certbot-lambda.zip` from [releases](https://github.c
     * `SecretsManagerReadWrite`
     * `AmazonRoute53FullAccess`
 1. Increase execution timeout in `Configuration` > `General configuration` to 10 minutes and memory limit to 150Mb.
+1. Add ENV variables at `Configuration` > `Environment variables` (check bellow for required ENV variables).
 1. Run lambda manually one time to create a secret by going to `Test` and executing `hello-wold` template.
 
 ### Automatic rotation

app/handler.py

@@ -10,10 +10,10 @@
 def handler(_event, _context):
     try:
         shutil.rmtree(str(settings.CERTBOT_DIR), ignore_errors=True)
-        # Load secret names yearly to check if aws client is configured correctly
+
+        # Load secret names early to check if aws client is configured correctly
         secret_names = list_secret_names()
 
-        # Obtain certs
         certs = obtain_certbot_certs(
             emails=settings.CERTBOT_EMAILS,
             domains=settings.CERTBOT_DOMAINS,