Add ability to specify custom names in the OAuth login buttons (#214)

config.yml

@@ -78,12 +78,16 @@ gitlab.client-key:
 gitlab.secret:
 # URL of the Gitlab instance. Default: https://gitlab.com/
 gitlab.url: https://gitlab.com/
+# The name of the GitLab instance. It is displayed in the OAuth login button. Default: GitLab
+gitlab.name: GitLab
 
 # To create a new OAuth2 application using Gitea : https://gitea.domain/user/settings/applications
 gitea.client-key:
 gitea.secret:
 # URL of the Gitea instance. Default: https://gitea.com/
 gitea.url: https://gitea.com/
+# The name of the Gitea instance. It is displayed in the OAuth login button. Default: Gitea
+gitea.name: Gitea
 
 # To create a new OAuth2 application using OpenID Connect:
 oidc.client-key: