Improve Staticman v3 documentation (mmistakes#2043)

* Corrected Staticman v3 info

* Added a link to eduardoboucas/staticman#219

* Fix typo

docs/_docs/05-configuration.md

@@ -392,7 +392,19 @@ Transform user comments into `_data` files that live inside of your GitHub repos
 
 ###### Staticman v3
 
-Due to the support for GitLab, the URL scheme has been changed.  Bewteen `v3` and `/entry`, one needs to input a Git service provider (either `github` or `gitlab`).  Apart from that, the setup for GitHub remains the same.
+Due to the [support for GitLab](https://github.com/eduardoboucas/staticman/pull/219), the URL scheme has been changed.  Between `v3/entry/` and `/{your Git username}`, one needs to input a Git service provider (either `github` or `gitlab`).  For example
+
+    https://{your Staticman v3 API}/v3/entry/github/{your Git username}/{your repository name}/...
+
+```yaml
+# _config.yml (defaults)
+repository  : # Git username/repo-name e.g. "mmistakes/minimal-mistakes"
+comments:
+  provider  : "staticman_v2"
+  staticman:
+    branch    : "master"
+    endpoint  : https://{your Staticman v3 API}/v3/entry/github/
+```
 
 ###### Staticman v2