add zns-cli instruction

README.md

@@ -15,10 +15,10 @@ some other information like expiration time to prevent replay attacks.
 
 The signature is created with the private key of the signer and validated on the server with the corresponding public key.
 ZNS has 2 methods of validating the signature:
+
 - Using your SSH Keys in [Zauth](https://zauth.zeus.gent)
 - Using a [DNSKEY record](https://datatracker.ietf.org/doc/html/rfc4034#section-2)
 
-
 ## User Guide
 
 How to add an `A` record to `<your zauth username>.users.zeus.gent`.
@@ -28,6 +28,11 @@ How to add an `A` record to `<your zauth username>.users.zeus.gent`.
 Create an SSH key pair (or use an existing one). Currently, only ED25519 and RSA SSH key types are supported.
 Add the public key to your Zauth account.
 
+### Step 1.5
+
+Install `zns-cli`.
+For exmaple for ubuntu `sudo apt-get install zns-cli`
+
 ### Step 2
 
 The (most) painless way for sending DNS update queries is using the `nsupdate` program.
@@ -70,6 +75,7 @@ There are three crates available at the root of the repo.
 `zns-daemon` is the server that handles DNS queries.
 
 The following environment variables should be set (or stored in a `.env` file):
+
 ```
 DATABASE_URL=postgres://zns@localhost/zns
 ZAUTH_URL="https://zauth.zeus.gent"