automation: add task issues to user story issue description from labels

[p0mvn]

Background

When managing complex projects, it is often useful to break down work into user stories.

For example, with concentrated-liquidity feature, we have an epic that consists of multiple user stories.

User stories in turn consist of multiple tasks. For example, here we have a "Swap Router Module" user story that consists of multiple tasks.

Currently, to keep track of each task, we have to manually edit the user story issue description and append it there under "Tasks" section.

Suggested Design

It should be possible to automate this manual process by creating a mapping from label to user story issue.

When a label is added to a task issue, the mapped user story issue is edited to have the link to the new task issue added.

This should reduce the need for worrying about this and potentially missing the link. The benefit of such linkage is being able to navigate the project easily and ensure that no task is missed.

Acceptance Criteria

• the process of auto adding task issue to user story issue is automated
• tested on fork repository
• the task issue is added under "Tasks" section of the user story issue