refactor(guide-linux-agent): update installation steps for clarity and improve formatting

Signed-off-by: Manuel Abascal <mjabascal10@gmail.com>

Author: mjabascal10

frontend/src/app/app-module/guides/guide-linux-agent/guide-linux-agent.component.html

@@ -12,10 +12,19 @@ <h4 class="card-title mb-0 text-primary">
     </p>
 
     <ol class="setup_list mt-3">
+      <li>
+        <p class="step-guide">
+          <span class="step_number">1</span>
+          Check pre-installation requirements
+        </p>
+        <ul class="mt-3 pl-3" style="list-style-type: circle !important;">
+          <li>The UTMStack Linux Agent relies on the local rsyslog service to collect and forward system logs.</li>
+        </ul>
+      </li>
       <li>
         <div>
           <p class="step-guide">
-            <span class="step_number">1</span>
+            <span class="step_number">2</span>
             Install or uninstall the UTMStack agent according to your operating system:
           </p>
           <div class="alert alert-warning alert-styled-right">