Update spell checking KCM docs

doc/kcontrol/spellchecking/index.docbook

@@ -16,8 +16,8 @@
 <!-- TRANS:ROLES_OF_TRANSLATORS -->
 </authorgroup>
 
-<date>2015-04-09</date>
-<releaseinfo>Plasma 5.3</releaseinfo>
+<date>2021-04-08</date>
+<releaseinfo>Plasma 5.20</releaseinfo>
 
 <keywordset>
 <keyword>KDE</keyword>
@@ -44,7 +44,7 @@ and additionally the corresponding dictionaries for your language.</para>
 available dictionaries, which one to use for &sonnet;. </para>
 
 <sect2 id="spell-options">
-<title>Spell Options</title>
+<title>Options</title>
 
 <variablelist>
  
@@ -93,7 +93,7 @@ for spelling errors. These addresses often contain words run together.</para></t
 </variablelist>
 </sect2>
 <!-- from koffice/kword/opt.docbook 1.6.2--> 
-<sect2><title>Ignoring words</title>
+<sect2><title>Ignored words</title>
 <para>The bottom half of the dialog box allows you to designate specific words (they may be specialized terminology, proper names, &etc;) which
 should be ignored by the spelling program.</para>