Docs: attrs tag default value

[jlopinto]

I found that we can provide a default value to attrs tag values using the var tag
I'm not sure if it was initially designed to work like that.

This PR is about documenting that find.

[luanfonceca]

Hey @jlopinto, I don't think it's a default value per se, what's happening is that you're "redefining" the loading with the value of "lazy".

If you try something different than "lazy" the loading will still be set to "lazy":

{# Usage #}
{% image src="..." alt="..." loading="eager" %}

{# Output #}
<img src="..." alt="..." loading="lazy" />

But would be really cool if we could pass default values when defining the {% attrs %}, something like:

<img {% attrs src loading="lazy" alt %}>

Which unfortunately doesn't work, it's kind of a short version of yours. A nice alternative for that is to use the |default template filter to achieve that:

Suggested change

	{% var loading="lazy" %}
	{% var loading=loading|default:"lazy" %}

[jlopinto]

Thank you @luanfonceca

I have made the necessary updates to the PR following your feedback.

[mixxorz]

Thank you!