Docs: Typo in helm repo add URL (trailing slash)

[fsaudm]

LOCATION:
https://redis.io/docs/latest/operate/kubernetes/deployment/helm/#install

DESCRIPTION:
In Step 1 of the "Install" section, the documentation provides a command with a trailing slash in the URL.

CURRENT:

helm repo add <repo-name> https://helm.redis.io/

SUGGESTED CHANGE:

helm repo add <repo-name> https://helm.redis.io

REASON:
The trailing slash (/) I think is causing Helm to generate a malformed URL (e.g., https://helm.redis.io//index.yaml) when attempting
to fetch the repository index.

This results in a "404 Not Found" or "Invalid Repository" error. Removing the slash makes the helm repo add work.