Remove the special treatment of span.title in Installation Assistant

Originally, the reasons for it was to make it possible to use bold and
underline on some words in the titles. But:

- Expert UX review told us that underline text was very often confused
  with links, while these titles are not clickable.
- Bold is meant to easy scanning in text but headings should be
  themselves short enough not to need additional scanning.
- They were style and aligned differently that everywhere else on our
  website and this inconsistency was no backed up with any good
  argument.
- Their content was 100% duplicate from [[!meta title and already caused
  painful maintenance work.

So let's get rid of them, simplify our code, reduce content
duplication, and increase style consistency.

wiki/src/install.html

@@ -6,10 +6,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1>Welcome to the <br />
-  <strong>Tails Installation Assistant</strong>
-</h1>
-
 <h4>Thank you for your interest in Tails.</h4>
 
 <p>Installing Tails can be quite long but we hope you will still have a good time :)</p>

wiki/src/install/debian.html

@@ -5,8 +5,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center"><strong>Debian</strong>, <strong>Ubuntu</strong>, or <strong>Mint</strong></h1>
-
 <div id="scenarios" class="row">
   <div class="col-md-6">
 

wiki/src/install/debian/clone-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Install from <strong>another Tails</strong></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[

wiki/src/install/debian/usb-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Install from <strong>Debian</strong>, <strong>Ubuntu</strong>, or <strong>Mint</strong></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[

wiki/src/install/expert/usb-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Install from <strong>Debian</strong>, <strong>Ubuntu</strong>, or <strong>Mint</strong> <small>using the command line and GnuPG</small></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[

wiki/src/install/inc/stylesheets/assistant.css

@@ -43,10 +43,6 @@
   right: 5px;
 }
 
-span.title {
-  display: none;
-}
-
 
 /* CONTENT */
 
@@ -56,14 +52,6 @@ body {
   margin-bottom: 100px;
 }
 
-span.title {
-  margin-top: 0px;
-}
-
-#content {
-  padding-top: 40px !important;
-}
-
 #pagebody #content .panel a {
   color: black !important;
   border-bottom: 0px !important;
@@ -86,22 +74,6 @@ h1, h2, h3, h4, h5, h6 {
   font-family: "Source Sans Pro Regular", "DejaVu Sans", "Verdana", "sans-serif";
 }
 
-h1 {
-  font-weight: 100;
-  margin-bottom: 30px;
-  margin-top: 0px;
-}
-
-h1 strong {
-  font-weight: 800;
-  -webkit-box-shadow: 0px -10px #53b351 inset;
-  box-shadow: 0px -10px #53b351 inset;
-}
-
-h1:before {
-  display: none;
-}
-
 h3, h4, p, ul {
   margin-bottom: 1.5em;
 }

wiki/src/install/inc/stylesheets/steps.css

-span.title {
-  display: block;
-  font-weight: 100;
-  padding-top: 100px;
-  color: black;
-  font-size: 36px;
-  text-align: center;
-  border-left: none;
-}
-
 .sidebar {
   display: none;
 }
@@ -83,6 +73,7 @@ h1 {
   font-weight: 400;
   margin-left: -150px;
   margin-top: 50px;
+  margin-bottom: 25px;
 }
 
 /* Trophy is a trophy */

wiki/src/install/linux.html

@@ -6,8 +6,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Other <strong>Linux</strong> <small>(Red Hat, Fedora, etc.)</small></h1>
-
 <div id="scenarios" class="row">
   <div class="col-md-6">
 

wiki/src/install/linux/clone-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Install from <strong>another Tails</strong></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[

wiki/src/install/linux/usb-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Install from <strong>Linux</strong></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[

wiki/src/install/mac.html

@@ -6,8 +6,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center"><strong>Mac</strong></h1>
-
 <p>Tails is not working on every Mac model and you might have to try <strong>different
 installation methods</strong>.</p>
 

wiki/src/install/mac/clone-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Install from <strong>another Tails</strong></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[

wiki/src/install/mac/dvd-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Install from <strong>Mac</strong> <small>by burning a DVD first</small></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[

wiki/src/install/mac/usb-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Install from <strong>Mac</strong> <small>using the command line</small></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[

wiki/src/install/os.html

@@ -4,8 +4,6 @@
 [[!meta stylesheet="inc/stylesheets/assistant" rel="stylesheet" title=""]]
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1>Which <strong>operating system</strong> are you installing Tails from?</h1>
-
 <div class="row">
   <div class="col-md-6">
     [[

wiki/src/install/win.html

@@ -6,8 +6,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center"><strong>Windows</strong></h1>
-
 <div id="scenarios" class="row">
   <div class="col-md-6">
 

wiki/src/install/win/clone-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Install from <strong>another Tails</strong></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[

wiki/src/install/win/usb-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Install from <strong>Windows</strong></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[

wiki/src/upgrade.html

@@ -5,8 +5,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Choose your <strong>manual upgrade</strong> scenario</h1>
-
 <div id="scenarios" class="row">
   <div class="col-md-6">
 

wiki/src/upgrade/clone-overview.html

@@ -7,8 +7,6 @@
 
 [[!inline pages="install/inc/tails-installation-assistant.inline" raw="yes" sort="age"]]
 
-<h1 class="text-center">Manually upgrade from <strong>another Tails</strong></h1>
-
 [[!inline pages="install/inc/overview" raw="yes" sort="age"]]
 
 [[