docs: ✏️ Add commitType to config docs

Add the commitType key and description to the configuration table

✅ Closes: #710

Author: danieltott

docs/bot/configuration.md

@@ -22,6 +22,7 @@ These are the keys you can specify:
 | `imageSize`                      | Size (in px) of the user's avatar.                                                                  | Default: `100`                                                                                              |
 | `commit`                         | Auto-commit badge when adding contributors.                                                         | Default: `false`                                                                                           |
 | `commitConvention`               | Commit convention ([`angular`](https://github.com/angular/angular/blob/master/CONTRIBUTING.md#-commit-message-guidelines), [`atom`](https://github.com/atom/atom/blob/master/CONTRIBUTING.md#git-commit-messages), [`ember`](https://guides.emberjs.com/v1.10.0/contributing/#toc_commits), [`eslint`](https://eslint.org/docs/1.0.0/developer-guide/contributing#step-2-make-your-changes), [`jshint`](https://jshint.com/contribute/), [`gitmoji`](https://gitmoji.carloscuesta.me/), or `none`).                                                         | Default: `angular`                                                                                           |
+| `commitType`                     | Set the `tag` for the commit in your chosen `commitConvention` (read more at [`commit-conv`](https://github.com/Berkmann18/commit-conv#parameters))    | Default: `docs`                                          |
 | `contributorsPerLine`            | Maximum number of columns for the contributors table.                                               | Default: `7`                                                                                                |
 | `contributorsSortAlphabetically` | `true`: Sort alphabetically. `false`: Display in order of addition.                       | Default: `false`                                                                                            |
 | `badgeTemplate`                  | Define your own lodash template to generate the badge.                                              | |