Update config.toml to use newer highlight configuration

Hugo has a newer set of config options to control highlighting. Use them.

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>

config.toml

@@ -5,13 +5,6 @@ theme = "beautifulhugo"
 
 canonifyURLs = true
 
-# Highlighting
-pygmentsCodeFences = true
-pygmentsUseClasses = true
-pygmentsCodeFencesGuessSyntax = true
-pygmentsoptions = "linenos=table"
-pygmentsStyle = "vs"
-
 languageCode = "en-us"
 
 [Author]
@@ -94,3 +87,9 @@ languageCode = "en-us"
   [markup.tableOfContents]
     startLevel = 1
     endLevel = 2
+
+  [markup.highlight]
+    lineNos = true
+    lineNumbersInTable = true
+    noClasses = false
+    style = "vs"