Don't call a plugin "something plugin"

Summary: The fact that it's a plugin isn't very relevant.

Reviewers: #plasma

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D1810

plasmacalendarintegration/holidayeventsplugin.json

@@ -1,5 +1,5 @@
 {
-    "Name": "Holidays plugin",
+    "Name": "Holidays",
     "Description": "Calendar plugin for displaying public holidays",
     "Icon": "view-calendar",
     "ConfigUi": "holidays/HolidaysConfig.qml",