Completion for template parameters in `{#include}`'d Qute templates

[datho7561]

eg.

If you have a Qute template:

I like to eat ice cream while at the {location}.

and you include it in another template:

<h1>My title</h1>

<p>
{#include template.html /}
</p>

you can pass in the template value like this:

{#include template.html location="park" /}

It would be nice to provide completion for location when the cursor is here:

{#include template.html | /}