Simplify and make linear

This advanced warning breaks the linear flow of the instructions.

The Shift+Restart technique on Windows should make it less useful
anyway.

wiki/src/install/inc/steps/pc_boot_menu.inline.html

-<h2>Make the computer start on the USB stick</h2>
+<p>Most computers do not start on the Tails USB stick automatically but you can
+press a Boot Menu key to display a list of possible devices to start from.</p>
 
-<p>This step is the most complicated one as it depends a lot on the
-model of the computer:</p>
-
-<ul>
-<li>On most computers, our basic instructions to get to the Boot Menu
-work fine.</li>
-<li>On some computers, you might have to do more advanced techniques,
-like editing the BIOS settings.</li>
-<li>On a few computers, it might currently be impossible to start Tails.
-But, it is very hard to know without trying.</li>
-</ul>
-
-<p>The goal is to reach the Boot Loader of Tails. Depending on the
-computer, the Boot Loader might be either <em>GRUB</em> or
-<em>SYSLINUX</em>.</p>
-
-<p>This is what <em>GRUB</em> looks like:</p>
-
-<p>[[!img install/inc/screenshots/grub.png link="no" alt="Black screen ('GNU GRUB') with Tails
-logo and 2 options: 'Tails' and 'Tails (Troubleshooting Mode)'."]]</p>
-
-<p>This is what <em>SYSLINUX</em> looks like:</p>
-
-<p>[[!img install/inc/screenshots/syslinux.png link="no" alt="Black screen ('SYSLINUX') with Tails
-logo and 2 options: 'Tails' and 'Tails (Troubleshooting Mode)'."]]</p>
-
-<div class="next">
-
-<p>After you reach the Boot Loader, either <em>GRUB</em> or <em>SYSLINUX</em>, you
-can skip the rest of this section and <a href="#welcome-screen">wait until
-the Welcome Screen appears</a>.</p>
-
-</div>
-
-<h3 id="boot-menu">Getting to the Boot Menu</h3>
-
-<p>On most computers, you can press a <em>Boot Menu key</em> to display
-a list of possible devices to start from. The following instructions
-explain how to display the Boot Menu and start on the USB stick. The
-following screenshot is an example of a Boot Menu:</p>
+<p>The following screenshot is an example of a Boot Menu:</p>
 
 <p>[[!img install/inc/screenshots/boot_menu.png link="no" alt=""]]</p>