Add auto-closing liquid tags

[Woetfin]

Is your feature request related to a problem? Please describe.
Currently, HTML tags are already auto-closed when typing the closing '>'.

But we can also tweak the auto-closing code so it works for liquid tags.

Describe the solution you'd like
For example, when typing {% if var %} it already adds the closing {% endif %}

Describe alternatives you've considered
Manually typing it / using snippets