Fix installation instructions for Helm 4 and add the company I work for to USERS.md (#660)

Author: roemba

USERS.md

@@ -12,3 +12,4 @@ information to this file.
 | Würth IT GmbH| production | Using helm-secrets to deploy our helm charts to our on premise open shift container platform              | Germany  | June 2024|  
 | Sopra Steria | production | Using helm-secrets to deploy helm charts using ArgoCD on several platform                                 | Europe   | Jan 2025 |  
 | Fast Forest  | production | Using helm-secrets together with ArgoCD to manage the k3s cluster the team infrastructure runs on         | Germany  | Jun 2022 |
+| Dutch Public Broadcaster (NPO)  | production | Using helm-secrets and vals to deploy Helm charts with parameters from AWS SSM | Netherlands | Nov 2025 |

docs/Installation.md

@@ -23,9 +23,9 @@ The `--version` flag is not supported in Helm 4, so you need to specify the exac
 Click [here](https://github.com/jkroepke/helm-secrets/releases/latest) for the latest version.
 
 ```bash
-helm plugin install https://github.com/jkroepke/helm-secrets/releases/download/v4.7.4/secrets.tgz
-helm plugin install https://github.com/jkroepke/helm-secrets/releases/download/v4.7.4/secrets-getter.tgz
-helm plugin install https://github.com/jkroepke/helm-secrets/releases/download/v4.7.4/secrets-post-renderer.tgz
+helm plugin install https://github.com/jkroepke/helm-secrets/releases/download/v4.7.4/secrets-4.7.4.tgz
+helm plugin install https://github.com/jkroepke/helm-secrets/releases/download/v4.7.4/secrets-getter-4.7.4.tgz
+helm plugin install https://github.com/jkroepke/helm-secrets/releases/download/v4.7.4/secrets-post-renderer-4.7.4.tgz
 ```
 
 ### Install latest version