Add GitHub discussions total badge [GithubTotalDiscussions] (#6472)

* use headers from options passed as argument in request method

* add github total discussions badge

* use nonNegativeInteger for total discussion count

Co-authored-by: repo-ranger[bot] <39074581+repo-ranger[bot]@users.noreply.github.com>

services/github/github-api-provider.js

@@ -188,6 +188,7 @@ class GithubApiProvider {
           'User-Agent': userAgent,
           Accept: 'application/vnd.github.v3+json',
           Authorization: `token ${tokenString}`,
+          ...options.headers,
         },
       },
     }