##### SUMMARY

When I run `ansible-galaxy [type] init`, I would like to be able to use my own configured 'skeleton' to init that content.

For Ansible roles, when running `ansible-galaxy role init myrole`, I can configure a [`GALAXY_ROLE_SKELETON`](https://docs.ansible.com/ansible/latest/reference_appendices/config.html#galaxy-role-skeleton) in my `ansible.cfg`, and the init command will use that skeleton as the source for the new role.

For Ansible collections, currently there's a bug (https://github.com/ansible/ansible/issues/66255) that causes collections to use that skeleton if its set (which can lead to some confusion)—but once that bug's fixed, there's no way to specify a skeleton for a collection.

So this feature request is to add a new configuration option `GALAXY_COLLECTION_SKELETON` (environment variable `ANSIBLE_GALAXY_COLLECTION_SKELETON`) which allows a collection skeleton to be specified.

Note: the docs for `GALAXY_ROLE_SKELETON` currently state:

> Role or collection skeleton directory to use as a template for the `init` action in `ansible-galaxy`, same as `--role-skeleton`.

Therefore that would need adjusting too, if the previously mentioned bug doesn't fix that.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME

ansible-galaxy init

##### ADDITIONAL INFORMATION

N/A
own_skeleton = False
            skeleton_ignore_expressions = C.GALAXY_ROLE_SKELETON_IGNORE
        else:
            own_skeleton = True
            obj_skeleton = self.galaxy.default_role_skeleton_path
            skeleton_ignore_expressions = ['^.*/.git_keep$']
        obj_skeleton = os.path.expanduser(obj_skeleton)
        skeleton_ignore_re = [re.compile(x) for x in skeleton_ignore_expressions]
        if not os.path.exists(obj_skeleton):
            raise AnsibleError("- the skeleton path '{0}' does not exist, cannot init {1}".format(
                to_native(obj_skeleton), galaxy_type)
            )
        loader = DataLoader()
        templar = Templar(loader, variables=inject_data)
        
        if not os.path.exists(b_obj_path):
            os.makedirs(b_obj_path)
        for root, dirs, files in os.walk(obj_skeleton, topdown=True):
            rel_root = os.path.relpath(root, obj_skeleton)
            rel_dirs = rel_root.split(os.sep)
            rel_root_dir = rel_dirs[0]
            if galaxy_type == 'collection':
                
                in_templates_dir = rel_root_dir in ['playbooks', 'roles'] and 'templates' in rel_dirs
            else:
                in_templates_dir = rel_root_dir == 'templates'
            
            
            dirs[:] = [d for d in dirs if not any(r.match(d) for r in skeleton_ignore_re)]
            for f in files: