Remove empty line between power on and press-and-hold (Closes: #15110)

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

@@ -6,9 +6,7 @@
 </li>
 
 <li>
-   <p>Switch on the computer.</p>
-
-   <p>Immediately press-and-hold the
+   <p>Switch on the computer and immediately press-and-hold the
    <span class="keycap">Option</span> key (<span class="keycap">Alt</span> key) until a list of possible startup
    disks appears.</p>