docs: remove pointless trailing hard-breaks

Line-break at the end of an article is quite pointless, and doesn't do
much to increase the readability. Let's get rid of them.

Signed-off-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>

docs/install.html

@@ -251,8 +251,6 @@ For example, compiling and linking a GLUT application can be done with:
    gcc `pkg-config --cflags --libs glut` mydemo.c -o mydemo
 </pre>
 
-<br>
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 </div>
 </body>
 </html>

docs/postprocess.html

@@ -55,10 +55,6 @@ Numbers higher than 8 see minimizing gains.
 <li>pp_celshade - set to 1 to enable cell shading (a more complex color filter).
 </ul>
 
-
-<br>
-<br>
-
 </div>
 </body>
 </html>