chore(influxdb): include notice for tag switch-over (#2635)

influxdb/content.md

@@ -1,3 +1,7 @@
+# Notice
+
+On February 3, 2026, the latest tag for InfluxDB will point to InfluxDB 3 Core. To avoid unexpected upgrades, use specific version tags in your deployments.
+
 # What is InfluxDB?
 
 %%LOGO%%