Fix videos page (#2321)

* Removed duplicate title in doc theme.

* Removed stray lower than tag.

* Replaced obsolete frameborder attribute.

docs/markdown/Videos.md

@@ -9,7 +9,7 @@ short-description: Videos about Meson
 (from Linux.conf.au 2015 -- Auckland, New Zealand)
 
 <div class="video-container">
-<iframe width="854" height="480" src="https://www.youtube.com/embed/KPi0AuVpxLI" frameborder="0" allowfullscreen></iframe>
+<iframe width="854" height="480" style="border:0;" src="https://www.youtube.com/embed/KPi0AuVpxLI" allowfullscreen></iframe>
 </div>
 
 ## Talks about design, goals behind Meson's multiplatform dependency system was held
@@ -17,7 +17,7 @@ short-description: Videos about Meson
 (From Linux.conf.au 2016 -- Geelong, Australia)
 
 <div class="video-container">
-<iframe width="854" height="480" src="https://www.youtube.com/embed/CTJtKtQ8R5k" frameborder="0" allowfullscreen></iframe>
+<iframe width="854" height="480" style="border:0;" src="https://www.youtube.com/embed/CTJtKtQ8R5k" allowfullscreen></iframe>
 </div>
 
 ## Features and benefits of Meson's multiplatform support for building and dependencies]
@@ -25,7 +25,7 @@ short-description: Videos about Meson
 (Libre Application Summit 2016 talk _New world, new tools_ explored further)
 
 <div class="video-container">
-<iframe width="854" height="480" src="https://www.youtube.com/embed/0-gx1qU2pPo" frameborder="0" allowfullscreen></iframe>
+<iframe width="854" height="480" style="border:0;" src="https://www.youtube.com/embed/0-gx1qU2pPo" allowfullscreen></iframe>
 </div>
 
 ## The first ever public presentation on Meson
@@ -33,5 +33,5 @@ short-description: Videos about Meson
 (lightning talk at FOSDEM 2014)
 
 <video width="854" height="480" controls>
-  < <source src=http://mirror.onet.pl/pub/mirrors/video.fosdem.org/2014/H2215_Ferrer/Sunday/Introducing_the_Meson_build_system.webm>
+  <source src=http://mirror.onet.pl/pub/mirrors/video.fosdem.org/2014/H2215_Ferrer/Sunday/Introducing_the_Meson_build_system.webm>
 </video>