Add option to create the full link with URL and title

[nhoizey]

2 options:

1. Add a second parameter to automate the full link creation:

{% link_to "page-slug", true %}

2. Add a second Nunjucks tag:

{% title_of "page-slug" %}

Second option would allow the developer to:

• use the title without a link
• build a link with other attributes (title, hreflang, class, etc.)