UX: clarifies discourse_post_event_enabled needs calendar_enabled

UX: clarifies discourse_post_event_enabled needs calendar_enabled

diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index f4940be..d8d7dee 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -1,7 +1,7 @@
 en:
   site_settings:
     calendar_enabled: "Enable the discourse-calendar plugin. This will add support for a [calendar][/calendar] tag in the first post of a topic."
-    discourse_post_event_enabled: "[experimental] Enables to attach an event to a post."
+    discourse_post_event_enabled: "[experimental] Enables to attach an event to a post. Note: also needs `calendar enabled` to be enabled."
     displayed_invitees_limit: "Limit the numbers of invitees displayed on an event."
     discourse_post_event_allowed_on_groups: "Groups that are allowed to create events."
     holiday_calendar_topic_id: "Topic ID of staffs holiday / absence calendar."

GitHub sha: c195a285

Should we do this in a validator?

The thing is many method of plugin instance do their magic on “plugin.enabled?” at runtime with it being computed from a specified setting (here calendar_enabled).