Update dns.md

Fixed typo
Guided to access keys
noted slave users must be unique (see https://forum.hestiacp.com/t/dns-cluster-slave-deletes-dns-after-few-minutes/9645/6)

Author: StuartJMackintosh

docs/docs/server-administration/dns.md

@@ -72,11 +72,12 @@ Preparing your **Slave** server(s):
 
 1. Whitelist your master server IP in **Configure Server** -> **Security** -> **Allowed IP addresses for API**
 2. Enable API access for admins (or all users).
-3. Create an API key under the **admin** user with at least the **sync-dns-cluster** permission.
+3. Create an API key under the **admin** user with at least the **sync-dns-cluster** permission. This is found in user settings / Access keys.
 4. Create a new DNS sync user as follows:
    - Has email address (something generic)
    - Has the role `dns-cluster`
    - You may want to set 'Do not allow user to log in to Control Panel' if they are not a regular user
+   - If you have more than one slave, the slave user must be unique
 5. Edit `/usr/local/hestia/conf/hestia.conf`, change `DNS_CLUSTER_SYSTEM='hestia'` to `DNS_CLUSTER_SYSTEM='hestia-zone'`.
 6. Edit `/etc/bind/named.conf.options`, do the following changes, then restart bind9 with `systemctl restart bind9`:
 
@@ -116,7 +117,7 @@ Preparing your **Master** server:
    v-add-remote-dns-host slave.yourhost.com 8083 'admin' 'strongpassword' 'api' 'user-name'
    ```
 
-3. Check it worked by listing the DNS zones on the **Slave** for the dns-user with the CLI command `v-list-dns-domains dns-user` or by connecting to the web iterface as dns-user and reviewing the DNS zones.
+3. Check it worked by listing the DNS zones on the **Slave** for the dns-user with the CLI command `v-list-dns-domains dns-user` or by connecting to the web interface as dns-user and reviewing the DNS zones.
 
 ### Converting an existing DNS cluster to Master -> Slave