[plasma/kwin] doc/kwintabbox: Updated version to 5.21. Rewrote the whole article to be more descriptive.

[David Edmundson]

Git commit 1f006e21849a871de24026866d704275debdf562 by David Edmundson, on behalf of Peter Wilding.
Committed on 27/01/2021 at 11:46.
Pushed by davidedmundson into branch 'master'.

Updated version to 5.21. Rewrote the whole article to be more descriptive.

M  +1    -1    doc/kwintabbox/index.docbook

https://invent.kde.org/plasma/kwin/commit/1f006e21849a871de24026866d704275debdf562

diff --git a/doc/kwintabbox/index.docbook b/doc/kwintabbox/index.docbook
index 1d685fc43..46c693f6b 100644
--- a/doc/kwintabbox/index.docbook
+++ b/doc/kwintabbox/index.docbook
@@ -13,7 +13,7 @@
 </authorgroup>
 
 <date>2020-12-31</date>
-<releaseinfo>&plasma; 5.18</releaseinfo>
+<releaseinfo>&plasma; 5.21</releaseinfo>
 
 <keywordset>
 <keyword>KDE</keyword>