[Proposal] Auto-assign projects to issues in issue templates

[sebthom]

Feature Description

Gitea issue templates are great! They already allow the automatic assignment of labels on issue creation.
I propose to allow the same for projects (kanban boards).

E.g.

---
name: "Template Name"
about: "This template is for testing!"
title: "[TEST] "
ref: "main"
labels:
- bug
- "help needed" 

# new property `projects`:
projects:
- 3 # same-repo level project with ID 3
- ../1 # org level project with ID 1
---

This is the template!

Screenshots

No response

[lunny]

The syntax of org level project looks wired, maybe orgname/1 is better? Then you can even link to another org.

[sebthom]

Fine with me too.

[lunny]

part of #14629