Move SNMP device name help text to placeholder

Changed the help text below the device name field to appear as placeholder
text inside the input field when in SNMP mode

lib/towerops_web/live/device_live/form.html.heex

@@ -32,13 +32,13 @@
         field={@form[:name]}
         type="text"
         label="Device Name"
+        placeholder={
+          if @monitoring_mode == "snmp_and_icmp",
+            do: "Leave blank to automatically populate from SNMP device name (sysName)",
+            else: nil
+        }
         required={@monitoring_mode == "icmp_only"}
       />
-      <%= if @monitoring_mode == "snmp_and_icmp" do %>
-        <p class="mt-1 text-sm text-zinc-600 dark:text-zinc-400">
-          Leave blank to automatically populate from SNMP device name (sysName) during discovery.
-        </p>
-      <% end %>
 
       <.input field={@form[:ip_address]} type="text" label="IP Address" required />