Comment Color Brightness

-> Please see nordtheme/nord#94 for all
   details about this design change decision.

Increased the comment color (`nord3`) brightness by 10% from a lightness
level of ~35% to ~45%.

GH-13

src/xml/nord.xml

@@ -21,6 +21,7 @@ References:
   <color name="nord1" value="#3B4252" />
   <color name="nord2" value="#434C5E" />
   <color name="nord3" value="#4C566A" />
+  <color name="nord3-brightened" value="#616E88" />
   <color name="nord4" value="#D8DEE9" />
   <color name="nord5" value="#E5E9F0" />
   <color name="nord6" value="#ECEFF4" />
@@ -80,10 +81,10 @@ References:
   <style name="def:special-constant" foreground="nord9" />
 
   <!--+- Comments -+-->
-  <style name="def:comment" foreground="nord3" />
+  <style name="def:comment" foreground="nord3-brightened" />
   <style name="def:doc-comment" use-style="def:comment" />
   <style name="def:doc-comment-element" foreground="nord9" />
-  <style name="def:net-address-in-comment" foreground="nord3" underline="true" />
+  <style name="def:net-address-in-comment" foreground="nord3-brightened" underline="true" />
   <style name="def:note" use-style="def:comment" />
 
   <!--+- Keywords -+-->