Update make docs procedure and add workflow to keep it up to date

[jdbaldry]

What this PR does

Updates the make docs procedure, consisting of the script and related Make scaffolding.

For reviewers:

1. Please ensure you can run make docs from the docs/ directory.
2. Update repository access, please do one of the following:
   1. Add @grafana/docs-tooling with write access to the repository. It is a group containing only myself but would additionally include any other Doc squad tooling maintainers in the future. Any changes to this groups membership would be communicated.
   2. Add only my GitHub handle if that is easier for governance purposes.
   3. Ask me to remove the changes to CODEOWNERS and rely on my membership of the @grafana/mimir-maintainers group.

[osg-grafana]

Suggested change

	note 'You might need to use Ctrl+c to end the process.'
	note 'You might need to use Ctrl+C to end the process.'

For keys, use WYSIWYG. If we were to use shift, we would write Ctrl+Shift+C.

[jdbaldry]

Makes sense, I can make this change upstream and it will get propagated to all other repositories.

[osg-grafana]

Approving from a docs side with feedback; please have an engineer vet this for technical accuracy.

[jdbaldry]

@grafana/mimir-maintainers Anyone able to give this a look?

[jdbaldry]

@grafana/mimir-maintainers Would anyone be able to take a look at this PR, I've updated it again.

[charleskorn]

Update repository access, please do one of the following:

1. Add @grafana/docs-tooling with write access to the repository. It is a group containing only myself but would additionally include any other Doc squad tooling maintainers in the future. Any changes to this groups membership would be communicated.
2. Add only my GitHub handle if that is easier for governance purposes.
3. Ask me to remove the changes to CODEOWNERS and rely on my membership of the @grafana/mimir-maintainers group.

I'm OK with the first option, will leave this for a day or two for other opinions.

[charleskorn]

LGTM.

I've given @grafana/docs-tooling write access to this repo.

[jdbaldry]

Cheers @charleskorn!