Update pinned posts help text (#5811)

* Update pinned posts help text

* Update en.json

* Fix id

webapp/i18n/en.json

@@ -1796,8 +1796,9 @@
   "search_results.usageFlag3": " icon next to the timestamp.",
   "search_results.usageFlag4": "Flags are a way to mark messages for follow up. Your flags are personal, and cannot be seen by other users.",
   "search_results.usagePin1": "There are no pinned messages yet.",
-  "search_results.usagePin2": "You can pin a message by clicking the \"Pin to channel\" option from the message's menu.",
-  "search_results.usagePin3": "Pinned messages are accessible by all channel members and are a way to mark messages for future reference.",
+  "search_results.usagePin2": "All members of this channel can pin important or useful messages.",
+  "search_results.usagePin3": "Pinned messages are visible to all channel members.",
+  "search_results.usagePin4": "To pin a message: Go to the message that you want to pin and click [...] > \"Pin to channel\".",
   "setting_item_max.cancel": "Cancel",
   "setting_item_max.save": "Save",
   "setting_item_min.edit": "Edit",