API: Expose its limitation settings (#12714)

* API: Expose its limitation settings

* TESTs

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

routers/api/v1/api.go

@@ -521,6 +521,7 @@ func RegisterRoutes(m *macaron.Macaron) {
 		m.Post("/markdown/raw", misc.MarkdownRaw)
 		m.Group("/settings", func() {
 			m.Get("/ui", settings.GetGeneralUISettings)
+			m.Get("/api", settings.GetGeneralAPISettings)
 			m.Get("/repository", settings.GetGeneralRepoSettings)
 		})