Revert "Remove instances of title: from YAML headers"

This reverts commit 24e6a8a616.

https://github.com/QubesOS/qubes-issues/issues/6701#issuecomment-862060759

introduction/code-of-conduct.md

@@ -4,6 +4,7 @@ layout: default
 redirect_from:
 - /code-of-conduct/
 ref: 118
+title: Code of Conduct
 ---
 
 ## Introduction

introduction/contributing.md

@@ -7,6 +7,7 @@ redirect_from:
 - /doc/ContributingHowto/
 - /wiki/ContributingHowto/
 ref: 125
+title: Contributing to the Qubes OS Project
 ---
 
 How to Contribute to the Qubes OS Project

introduction/experts.md

@@ -4,4 +4,5 @@ layout: experts
 redirect_from:
 - /experts/
 ref: 119
+title: Experts
 ---

introduction/faq.md

@@ -12,6 +12,7 @@ redirect_from:
 - /doc/DevelFaq/
 - /wiki/DevelFaq/
 ref: 124
+title: Frequently Asked Questions
 ---
 
 # Frequently Asked Questions

introduction/intro.html

@@ -8,6 +8,7 @@ redirect_from:
 - /about/
 - /en/about/
 ref: 126
+title: Introduction
 ---
 
 <h2>What is Qubes OS?</h2>

introduction/reporting-bugs.md

@@ -12,6 +12,7 @@ redirect_from:
 - /bug-report/
 - /bug-reports/
 ref: 121
+title: Reporting bugs and other issues
 ---
 
 # Reporting bugs and other issues #

introduction/screenshots.md

@@ -7,6 +7,7 @@ redirect_from:
 - /doc/QubesScreenshots/
 - /wiki/QubesScreenshots/
 ref: 123
+title: Screenshots
 ---
 
 Select Qubes OS Screenshots

introduction/statistics.md

@@ -5,6 +5,7 @@ redirect_from:
 - /statistics/
 - /counter/
 ref: 127
+title: Statistics
 ---
 
 <div class="center-block more-bottom">

introduction/support.md

@@ -12,6 +12,7 @@ redirect_from:
 - /doc/QubesLists/
 - /wiki/QubesLists/
 ref: 122
+title: Help, Support, Mailing Lists, and Forum
 ---
 
 # Help, Support, Mailing Lists, and Forum

introduction/video-tours.html

@@ -4,6 +4,7 @@ layout: default
 redirect_from:
 - /video-tours/
 ref: 226
+title: Video Tours of Qubes OS
 ---
 
 <div id="tour">