title: R: ggarange increasing distance between plot title of the muliplot and titles of each plot
body: <p>assume I've the following data to generate two barplot as a multiplot:</p>
  
  <pre><code>quarter1
  
      variable value merge1
  1      h=4     3     no
  2      h=7     2    yes
  3      h=8     3     no
  4     h=21     2     no
  
  quarter2
  
     variable value merge2
  1      h=6     1     no
  2      h=7     2    yes
  3     h=10     1     no
  4     h=12     3     no
  5     h=13     1     no
  6     h=16     1     no
  7     h=17     1     no
  </code></pre>
  
  <p>Code for the two plots:</p>
  
  <pre><code>bar_q &lt;- ggplot(quarter1, aes(x=variable, y=value, fill=merge1)) + geom_bar(stat="identity")
  bar_qf &lt;- bar_q  + ggtitle("k = 0") + 
  theme(axis.text=element_text(size=24, color="gray0"), axis.title=element_blank()) + 
  scale_y_continuous(breaks= function(x) unique(floor(pretty(seq(0, (max(x) + 1) * 1.1))))) + 
  scale_fill_manual(values= grp_colors, guide=F) + 
  theme(plot.title = element_text(hjust = 0.5, size=24))
  
  bar2_q &lt;- ggplot(quarter2, aes(x=variable, y=value, fill=merge2)) + geom_bar(stat="identity") 
  bar2_qf &lt;- bar2_q + ggtitle(expression(k %in% group("[", "1;4", "]"))) + theme(axis.text=element_text(size=24 , color="gray0"), axis.title=element_blank()) + 
  scale_y_continuous(limits=c(0,3), breaks=seq(3)) + 
  scale_fill_manual(values= grp_colors, guide=F) +  
  theme(plot.title = element_text(hjust = 0.5, size=24))
  </code></pre>
  
  <p>Generating multiplot with:</p>
  
  <pre><code>plot_quarter &lt;- egg::ggarrange(bar_qf,bar2_qf, ncol=2, top=textGrob("Quartalsdaten:Häufigkeiten", gp=gpar(fontsize=28,font=2)))
  </code></pre>
  
  <p>Resulting plot looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/iSq3w.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iSq3w.png" alt="enter image description here"></a></p>
  
  <p>If you look at the "g" in the plot title it's a bit cutted. However I tried to increase the distance between the title of the multiplot and the titles of each plot but don't find a way to do it in "ggarange". Do someone know how I can do this in ggarange/textGrob </p>