docs: add TMDB key refresh warning

Author: Martin Argalaš

README.md

@@ -16,6 +16,11 @@ A Home Assistant custom integration that acts as a secure server-side proxy betw
 
 <p><img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/radarr.png" height="36" title="Radarr"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/sonarr.png" height="36" title="Sonarr"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/bazarr.png" height="36" title="Bazarr"/> &nbsp; <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/qbittorrent.png" height="36" title="qBittorrent"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/deluge.png" height="36" title="Deluge"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/rutorrent.png" height="36" title="rTorrent"/> &nbsp; <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/sabnzbd.png" height="36" title="SABnzbd"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/nzbget.png" height="36" title="NZBGet"/> &nbsp; <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/overseerr.png" height="36" title="Overseerr"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/jellyseerr.png" height="36" title="Jellyseerr"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/tmdb.png" height="36" title="TMDB"/> &nbsp; <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/prowlarr.png" height="36" title="Prowlarr"/> &nbsp; <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/plex.png" height="36" title="Plex"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/jellyfin.png" height="36" title="Jellyfin"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/emby.png" height="36" title="Emby"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/kodi.png" height="36" title="Kodi"/> &nbsp; <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/tautulli.png" height="36" title="Tautulli"/> <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/jellystat.png" height="36" title="Jellystat"/> <img src="https://cdn.jsdelivr.net/gh/homarr-labs/dashboard-icons/svg/tracearr.svg" height="36" title="Tracearr"/> &nbsp; <img src="https://cdn.jsdelivr.net/gh/walkxcode/dashboard-icons/png/trakt.png" height="36" title="Trakt"/></p>
 
+> [!WARNING]
+> **Action required for users of Upcoming Movies, New Shows, Trending, or Popular categories without Seerr**
+>
+> The TMDB API key used as the default data source for these categories had to be refreshed, which invalidated the previous key. If these categories show nothing, please update both the **card** and the **integration** to the latest version via HACS.
+
 ---
 
 ## Why is this needed?