added blank to externar links and prevents reverse tabnabbing attack

[matiasbenary]

This change prevents reverse tabnabbing. https://owasp.org/www-community/attacks/Reverse_Tabnabbing In vscode look for this (<a[^>]+href=["']https?:\/\/[^"']+["'])([^>]*>) and replace it with this $1 target="_blank" rel="noopener noreferrer"$2 also check by hand

[gagdiez]

bit of an overkill, but sure, why not