Revert "Remove instances of title: from YAML headers"

This reverts commit 24e6a8a616.

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

external/os-guides/centos.md

@@ -5,4 +5,5 @@ redirect_from:
 - /doc/templates/centos/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/centos.md
 ref: 81
+title: CentOS Template
 ---

external/os-guides/gentoo.md

@@ -5,4 +5,5 @@ redirect_from:
 - /doc/templates/gentoo/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/gentoo.md
 ref: 221
+title: Gentoo Template
 ---

external/os-guides/linux-hvm-tips.md

@@ -8,4 +8,5 @@ redirect_from:
 - /wiki/LinuxHVMTips/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/linux-hvm-tips.md
 ref: 82
+title: Linux HVM Tips
 ---

external/os-guides/netbsd.md

@@ -5,4 +5,5 @@ redirect_from:
 - /doc/netbsd/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/netbsd.md
 ref: 84
+title: How to Create a NetBSD VM
 ---

external/os-guides/pentesting.md

@@ -5,4 +5,5 @@ redirect_from:
 - /doc/pentesting/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/pentesting.md
 ref: 83
+title: Penetration Testing
 ---

external/os-guides/pentesting/blackarch.md

@@ -6,4 +6,5 @@ redirect_from:
 - /doc/blackarch/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/pentesting/blackarch.md
 ref: 88
+title: How to Create a BlackArch VM
 ---

external/os-guides/pentesting/kali.md

@@ -6,4 +6,5 @@ redirect_from:
 - /doc/kali/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/pentesting/kali.md
 ref: 87
+title: How to create a Kali Linux VM
 ---

external/os-guides/pentesting/ptf.md

@@ -6,4 +6,5 @@ redirect_from:
 - /doc/ptf/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/pentesting/ptf.md
 ref: 89
+title: How to create Penetration Testers Framework (PTF) VM
 ---

external/os-guides/ubuntu.md

@@ -9,4 +9,5 @@ redirect_from:
 - /wiki/Templates/Ubuntu/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/ubuntu.md
 ref: 80
+title: Ubuntu Template
 ---

external/os-guides/windows/windows-tools.md

@@ -14,4 +14,5 @@ redirect_from:
 - /wiki/WindowsTools/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/windows/windows-tools.md
 ref: 86
+title: Qubes Windows Tools
 ---

external/os-guides/windows/windows-vm.md

@@ -5,4 +5,5 @@ redirect_from:
 - /doc/windows-vm/
 redirect_to: https://github.com/Qubes-Community/Contents/blob/master/docs/os/windows/windows-vm.md
 ref: 85
+title: Installing a Windows VM
 ---