Remove redundant titles

First pass for all titles still using the old '=====' syntax

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

user/common-tasks/backup-emergency-restore-v2.md

@@ -9,7 +9,6 @@ ref: 207
 title: Emergency Backup Recovery (v2)
 ---
 
-Emergency Backup Recovery without Qubes (v2)
 ============================================
 
 This page describes how to perform emergency restore of backup created on Qubes

user/common-tasks/backup-emergency-restore-v3.md

@@ -9,7 +9,6 @@ ref: 201
 title: Emergency Backup Recovery (v3)
 ---
 
-Emergency Backup Recovery without Qubes (v3)
 ============================================
 
 This page describes how to perform an emergency restore of a backup created on

user/common-tasks/backup-emergency-restore-v4.md

@@ -9,7 +9,6 @@ ref: 192
 title: Emergency Backup Recovery (v4)
 ---
 
-Emergency Backup Recovery without Qubes (v4)
 ============================================
 
 This page describes how to perform an emergency restore of a backup created on

user/common-tasks/backup-restore.md

@@ -10,7 +10,6 @@ ref: 199
 title: Backup, restoration, and migration
 ---
 
-Backup, restoration, and migration
 ==================================
 
 With Qubes, it's easy and secure to back up and restore your whole system, as well as to migrate between two physical machines.

user/common-tasks/copy-paste.md

@@ -10,7 +10,6 @@ ref: 196
 title: Copying and pasting text between qubes
 ---
 
-Copying and pasting text between qubes
 ======================================
 
 *This page is about copying and pasting plain text.

user/common-tasks/copying-files.md

@@ -10,7 +10,6 @@ ref: 191
 title: Copying and moving files between qubes
 ---
 
-Copying and moving files between qubes
 ======================================
 
 *This page is about copying and moving files.

user/common-tasks/full-screen-mode.md

@@ -10,7 +10,6 @@ ref: 205
 title: Full Screen Mode
 ---
 
-Enabling Full Screen Mode for select VMs
 ========================================
 
 What is full screen mode?

user/common-tasks/optical-discs.md

@@ -9,7 +9,6 @@ ref: 204
 title: Optical Discs
 ---
 
-Optical Discs
 =============
 
 Passthrough reading and recording (a.k.a., "burning") are not supported by Xen.

user/common-tasks/volume-backup-revert.md

@@ -10,7 +10,6 @@ ref: 206
 title: Volume Backup and Revert
 ---
 
-Qubes Volume Backup and Revert
 ==============================
 
 With Qubes, it is possible to revert one of a VM's storage volumes to a previous