[iagno] Add one more tip to help.

[Arnaud B. <arnaudb src gnome org>]

commit fba9395e64a2034ad6d6fbe6c6332af33a675b15
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Mon Feb 3 16:30:56 2020 +0100

    Add one more tip to help.

 help/C/alternate.page      | 35 +++++++++++++++++++++++++++++++++++
 help/C/start-position.page |  2 +-
 help/meson.build           |  1 +
 3 files changed, 37 insertions(+), 1 deletion(-)
---
diff --git a/help/C/alternate.page b/help/C/alternate.page
new file mode 100644
index 0000000..d82bf8f
--- /dev/null
+++ b/help/C/alternate.page
@@ -0,0 +1,35 @@
+<page xmlns="http://projectmallard.org/1.0/";
+      type="topic" style="task"
+      id="alternate">
+
+  <info>
+    <link type="guide" xref="index#tips" />
+    <revision pkgversion="3.36" version="0.1" date="2020-02-03" status="final"/>
+
+    <credit type="author copyright">
+      <name>Arnaud Bonatti</name>
+      <email>arnaud bonatti gmail com</email>
+      <years>2020</years>
+    </credit>
+
+    <license>
+      <p>Creative Commons Share Alike 3.0</p>
+    </license>
+  </info>
+
+  <title>Alternate who starts</title>
+
+  <p>If you are playing multiple games in a row <link xref="ai-game">against the computer</link>, 
<app>Reversi</app> allows you to automatically altern who will start the next game bewteen you and the 
computer.</p>
+
+  <p>When <link xref="configure">configuring a new game</link>, have a look to the first button with a down 
arrow; it should either be labelled <gui>Color: Dark</gui>, <gui>Color: Light</gui> or <gui>Two 
players</gui>. In the latter case, <app>Reversi</app> is configured to start a two-player game; if so, first, 
configure a game <link xref="ai-game">against the computer</link>.</p>
+
+  <p>Select the button. In the menu that appears, there is an entry called <gui>Alternate who 
starts</gui>.</p>
+
+  <p>If the <gui>Alternate who starts</gui> option is disabled, every new game will be started by the same 
player: you will be the first player if the label of the button is <gui>Color: Dark</gui>, and it will be the 
computer if the label is <gui>Color: Light</gui>; to change who starts, see how to configure a game <link 
xref="ai-game">against the computer</link>.</p>
+
+  <p>If the <gui>Alternate who starts</gui> option is enabled, then at each new game, who will be the first 
player will be automatically changed. So if you started a game, the next time you <link 
xref="configure">configure a new game</link>, the button will be labelled <gui>Color: Light</gui>, and the 
computer will be starting the following game.</p>
+
+  <p>To enable or disable the option, just select the <gui>Alternate who starts</gui> entry.</p>
+
+  <p>This option is selected by default.</p>
+</page>
diff --git a/help/C/start-position.page b/help/C/start-position.page
index a0650c4..b9a93ec 100644
--- a/help/C/start-position.page
+++ b/help/C/start-position.page
@@ -25,7 +25,7 @@
   <section id="varying-start-position">
     <title>Varying start position</title>
 
-    <p>To enable or disable this option, go in the Start Screen, click on the <gui>Difficulty</gui> button, 
and in the menu that appears, select <gui>Vary start position</gui>.</p>
+    <p>To enable or disable this option, while <link xref="configure">configuring a new game</link>, click 
on the <gui>Difficulty</gui> button, and in the menu that appears, select <gui>Vary start position</gui>.</p>
 
     <p>If you are playing a <link xref="ai-game">game against the computer</link>, enabling this option will 
start new games with a random position in the six <link xref="#start-positions">possible start 
positions</link>.</p>
 
diff --git a/help/meson.build b/help/meson.build
index c531319..e2d6ef9 100644
--- a/help/meson.build
+++ b/help/meson.build
@@ -17,6 +17,7 @@ help_files = [
     '2player.page',
     'ai-game.page',
     'ai-level.page',
+    'alternate.page',
     'bug-filing.page',
     'configure.page',
     'develop.page',