feat(templating) add ability to compose templates that are defined in the same html that composes them

[dkent600]

In reference this associated stackoverflow question

I would like to propose that aurelia have the ability to compose templates that are defined in the same html that composes them. This would be in contrast to the current restriction (correct me if I'm wrong) that composed templates must be defined in their own separate html file.

The proposed html could look like this, though I note there are plenty of other potential ways to do this:

<template>
    <template name="myTemplate">
        ${a-property-on-containers-binding-context}
    </template>

    <compose view="myTemplate"/>
</template>

[EisenbergEffect]

It sounds like a reasonable request.

[Alexander-Taran]

Stale since 2016

[EisenbergEffect]

Let's keep this open for now. It's a low priority but might be something we could do in vNext.