added installation instructions

README.md

@@ -6,7 +6,7 @@
 1. [compatibility](#compatibility)
 1. [build](#build)
 1. [create a new release](#create-a-new-release)
-1. [links](#links)
+1. [installation instructions](#installation-instructions)
 
 Fetches and stores a given Certificate, Full Chain, CA and Private Key.
 
@@ -93,6 +93,15 @@ git tag v1.2.3
 git pushall-tags
 ```
 
-## links
+## installation instructions
 
-The binaries and the shell script can be downloaded on [Geant Artifactory](https://artifactory.software.geant.org/artifactory/acme-downloader)
+You can install the script as follows (**as root**):
+
+```bash
+curl https://artifactory.software.geant.org/artifactory/acme-downloader/acme-downloader.sh > /usr/bin/acme-downloader.sh
+chown root:root /usr/bin/acme-downloader.sh
+chmod 750 /usr/bin/acme-downloader.sh
+acme-downloader.sh --vault-token <my_secret_vault_token> --redis-token <my_secret_redis_token> --team-name <my_team> --cert-name <myfancyservice.domain.org> --type OV --install-crontab
+```
+
+The binaries and the shell script can be downloaded from [Geant Artifactory](https://artifactory.software.geant.org/artifactory/acme-downloader)