gitHub* template functions return data from the GitHub API.
By default, an anonymous GitHub API request will be made, which is subject to
(currently 60 requests per hour per source IP address). If any of the
$GITHUB_TOKEN are found, then the first one found will be used to authenticate
the GitHub API request, with a higher rate limit (currently 5,000 requests per
hour per user).
In practice, GitHub API rate limits are high enough that you should rarely need to set a token, unless you are sharing a source IP address with many other GitHub users. If needed, the GitHub documentation describes how to create a personal access token.