Incorporate copyedits from known issues page

wiki/src/doc/advanced_topics/boot_options.mdwn

@@ -4,16 +4,15 @@ The Boot Loader is the first screen that appears
 when starting Tails.
 
 You can use the Boot Loader to modify the *boot options*. Boot options are
-special parameters that can be useful to troubleshoot or work around
-hardware support problems. For example, our [[list of known issues with
-graphics cards|support/known_issues/graphics]] document boot options for
-different graphics cards.
+special parameters used to troubleshoot or work around hardware support problems.
+For example, our [[list of known issues with graphics cards|support/known_issues/graphics]]
+document boot options for different graphics cards.
 
 <div class="tip">
 
 <p>The <span class="guilabel">Troubleshooting Mode</span> of the Boot Loader disables some features of the
 Linux kernel and might work better on some computers. You can try this option if you
-think you are experiencing errors related to hardware compatibility while
+think you are experiencing hardware compatibility errors while
 starting Tails.</p>
 
 </div>
@@ -46,8 +45,8 @@ To modify the boot options in *SYSLINUX*:
 
 1. Press **Tab** when *SYSLINUX* appears.
 
-   A list of boot options
-   appears at the bottom of the screen.
+   A command line with a list
+   of boot options will appear at the bottom of the screen.
 
    [[!img syslinux-with-options.png link="no" alt="SYSLINUX with
    a list of options starting with '/live/vmlinuz' at the bottom"]]
@@ -85,7 +84,7 @@ To modify the boot options in *GRUB*:
 
 1. Press **e** when GRUB appears.
 
-   A new screen appears with more options.
+   A new screen will appear with more options.
 
    [[!img grub-with-options.png link="no" alt="GRUB with a list of
    options starting with 'setparams Tails'"]]
@@ -93,9 +92,9 @@ To modify the boot options in *GRUB*:
 1. Modify the boot options as needed.
 
    To add a boot option, navigate with the arrows of the keyboard to the end of the line that
-   starts with <span class="code">linux</span> and type the boot option that you want to add. The line is most likely
-   wrapped and displayed on several lines on the screen but it is a
-   single configuration line.
+   starts with <span class="code">linux</span>.
+   Type the boot option that you want to add. The line is most likely
+   wrapped and displayed on several lines but it is a single configuration line.
 
    If you want to add more than one boot option, type them one after the
    other and separate them with a <span class="keycap">Space</span>.