docs(conf): add warning about alerting in conf file

conf/defaults.ini

@@ -335,5 +335,21 @@ global_session = -1
 
 
 #################################### Alerting ######################################
+# docs about alerting can be found in /docs/sources/alerting/
+
+#              __.-/|
+#              \`o_O'
+#               =( )=  +----------------------------+
+#                 U|   | Alerting is still in alpha |
+#       /\  /\   / |   +----------------------------+
+#      ) /^\) ^\/ _)\     |
+#      )   /^\/   _) \    |
+#      )   _ /  / _)  \___|_
+#  /\  )/\/ ||  | )_)\___,|))
+# <  >      |(,,) )__)    |
+#  ||      /    \)___)\
+#  | \____(      )___) )____
+#   \______(_______;;;)__;;;)
+
 [alerting]
 enabled = false