make songTitleSize customizable

default_style.ly

@@ -2,6 +2,7 @@ songFormatAndSize = "a5"
 songMargin = 5
 songInfoFontSize = 0
 songInfoLineWidthFraction = 0.9
+songTitleSize = 6
 songTitleFont = "LilyPond Sans"
 songChordFont = "LilyPond Sans"
 songLyricFont = "LilyPond Sans"

title_with_category_images.ly

@@ -4,7 +4,7 @@
 \markup {
   \override #'(baseline-skip . 3.5)
   \center-column {
-    \override #`(font-name . ,songTitleFont) { \fontsize #6 \fromproperty #'header:title }
+    \override #`(font-name . ,songTitleFont) { \fontsize #songTitleSize \fromproperty #'header:title }
     \large \bold \fromproperty #'header:subtitle
     \smaller \bold \fromproperty #'header:subsubtitle
   }