[gnome-terminal] help: Add section about "Show bold text in bright colors"

[Egmont Koblinger <egmontkob src gnome org>]

commit b2951a0e4a325faed87ac6fcc162feadd8d4d51f
Author: Egmont Koblinger <egmont gmail com>
Date:   Mon Feb 10 22:35:01 2020 +0100

    help: Add section about "Show bold text in bright colors"

 help/C/app-colors.page | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
---
diff --git a/help/C/app-colors.page b/help/C/app-colors.page
index c264f3b5..9efe3956 100644
--- a/help/C/app-colors.page
+++ b/help/C/app-colors.page
@@ -160,4 +160,35 @@
 
   </section>
 
+  <section id="bold-is-bright">
+    <title>Bright colors for bold text</title>
+
+    <p>Traditionally terminals didn't clearly separate bold font weight from
+    intense colors, often both of them were enabled together. Recent
+    improvements, such as the introduction of true color support, and certain
+    color schemes (e.g. Solarized) made it desirable to separate the two
+    concepts, that is, make the brightness independent from the font weight.</p>
+
+    <p>In order to choose your preferred behavior:</p>
+
+    <steps>
+      <item>
+        <p>Press the menu button in the top-right corner of the window and select
+        <gui style="menuitem">Preferences</gui>.</p>
+      </item>
+      <item>
+        <p>In the sidebar, select your current profile in the <gui>Profiles</gui>
+        section.</p>
+      </item>
+      <item>
+        <p>Select <gui style="tab">Colors</gui>.</p>
+      </item>
+      <item>
+        <p>Disable <gui>Show bold text in bright colors</gui> for the new
+        default behavior, the complete separation of color intensity and font
+        weight; or enable this option for improved backward compatibility.</p>
+      </item>
+    </steps>
+  </section>
+
 </page>