Add templates and guidelines to organization level

[franklinselva]

The contributing guidelines and the issue templates are only added to the main repository and can be levelled up to the organization to offer the same templates and guidelines to all the projects within the organization.

Currently, the contributing guidelines are here.
https://github.com/space-ros/space-ros/blob/main/CONTRIBUTING.md

The issue template for the main repository is here:
https://github.com/space-ros/space-ros/blob/main/.github/ISSUE_TEMPLATE.md

The issue template can be updated to the new workflow (more info here) and the contributing guidelines can be moved to the organization level.

This is an extension of the organization-level changes added on the main repository space-ros/space-ros#178.