Use the new homepage consistently

From now on, we want to use the gitforwindows.org domain, for obvious
reasons: it is nicer to type and easier to remember.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

requirements.html

@@ -44,7 +44,7 @@
 		<section class="details">
 			<article>
 				<h1 id="prerequisites">Prerequisites</h1>
-<p>This page lists the prerequisites required to run <a href="https://git-for-windows.github.io/">Git for Windows</a>.</p>
+<p>This page lists the prerequisites required to run <a href="https://gitforwindows.org/">Git for Windows</a>.</p>
 <h2 id="windows-version">Windows version</h2>
 <p>As of Git for Windows v2.10.1, Windows Vista or later are required. The last version of Git for Windows to support Windows XP and Windows Server 2003 is <a href="https://github.com/git-for-windows/git/releases/tag/v2.10.0.windows.1">v2.10.0</a>.</p>
 <p>Why?</p>

requirements.md

@@ -1,6 +1,6 @@
 # Prerequisites
 
-This page lists the prerequisites required to run [Git for Windows](https://git-for-windows.github.io/).
+This page lists the prerequisites required to run [Git for Windows](https://gitforwindows.org/).
 
 ## Windows version