Use inline HTML <img> with descriptive alt text on Web UI page (#74)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: evilsocket <86922+evilsocket@users.noreply.github.com>

Author: Copilot

src/content/docs/usage/web_ui.md

@@ -5,7 +5,7 @@ sidebar:
   order: 1
 ---
 
-![UI](https://raw.githubusercontent.com/bettercap/media/master/ui-events.png)
+<img src="https://raw.githubusercontent.com/bettercap/media/master/ui-events.png" alt="Bettercap web UI showing the events panel with a list of network events captured during a session" />
 
 The easiest way to use bettercap is through the official **[web UI](https://github.com/bettercap/ui)**.