Discord templates only allowed when getting the template

[MathMan05]

Describe the bug
Templates with the prefix of discord: can be used on spacebar to get the discord template, but the POST API does not implement the same feature making it so you can't use discord templates on spacebar.

To Reproduce
make a post with a discord: template prefix

Expected behavior
To create a guild with the template

Env and Software info
tested on the official instance and another

Additional context
Jank client supports it, spacebar does not