docs: add ssh host key error to known issues (#5250)

* docs: ssh error due to change in host key

* style: remove trailing whitespace

* Update website/content/docs/api-clients/client-agent.mdx

Co-authored-by: Johan Brandhorst-Satzkorn <johan.brandhorst@gmail.com>

* docs: rephrase  message

* Update website/content/docs/api-clients/client-agent.mdx

Co-authored-by: Dan Heath <76443935+Dan-Heath@users.noreply.github.com>

---------

Co-authored-by: Johan Brandhorst-Satzkorn <johan.brandhorst@gmail.com>
Co-authored-by: Dan Heath <76443935+Dan-Heath@users.noreply.github.com>

website/content/docs/api-clients/client-agent.mdx

@@ -510,6 +510,16 @@ $ boundary client-agent pause
 
 Follow the troubleshooting steps to understand why the Client Agent is not able to reach the controller.
 
+#### WARNING! Remote host indentification has changed! It is possible that someone is doing something nasty!
+
+This error arises when you use an alias to connect to an SSH target after the first successful connection using that alias. The issue occurs because Boundary workers generate a new host key on every new SSH connection. You can safely ignore the warning using the `StrictHostKeyChecking=no` command line option:
+
+```shell-session
+$ ssh -o StrictHostKeyChecking=no targetalias.boundary.dev
+```
+
+You can also remove the existing server host key from the `~/.ssh/known_hosts` file to avoid the error.
+
 ## Conflicting software
 
 Some software is known to cause conflicts with the Boundary Client Agent.