allow choosing default branch on UI

appview/pages/templates/repo/new.html

···
           class="w-full max-w-md"
           />
       <p class="text-sm text-gray-500">All repositories are publicly visible.</p>
+
+      <label for="name" class="block uppercase font-bold text-sm">Default branch</label>
+      <input
+          type="text"
+          id="branch"
+          name="branch"
+          required
+          class="w-full max-w-md"
+          />
+      <p class="text-sm text-gray-500">The default branch is <span class="font-bold">main</span></p>
     </div>
 
     <fieldset class="space-y-3">

appview/state/signer.go

···
 	return s.client.Do(req)
 }
 
-func (s *SignedClient) NewRepo(did, repoName string) (*http.Response, error) {
+func (s *SignedClient) NewRepo(did, repoName, defaultBranch string) (*http.Response, error) {
 	const (
 		Method   = "PUT"
 		Endpoint = "/repo/new"
 	)
 
 	body, _ := json.Marshal(map[string]interface{}{
-		"did":  did,
-		"name": repoName,
+		"did":            did,
+		"name":           repoName,
+		"default_branch": defaultBranch,
 	})
+
+	fmt.Println(body)
 
 	req, err := s.newRequest(Method, Endpoint, body)
 	if err != nil {

appview/state/state.go

···
 			return
 		}
 
+		defaultBranch := r.FormValue("branch")
+		if defaultBranch == "" {
+			defaultBranch = "main"
+		}
+
 		ok, err := s.enforcer.E.Enforce(user.Did, domain, domain, "repo:create")
 		if err != nil || !ok {
 			s.pages.Notice(w, "repo", "You do not have permission to create a repo in this knot.")
···
 			return
 		}
 
-		resp, err := client.NewRepo(user.Did, repoName)
+		resp, err := client.NewRepo(user.Did, repoName, defaultBranch)
 		if err != nil {
 			s.pages.Notice(w, "repo", "Failed to create repository on knot server.")
 			return

knotserver/routes.go

···
 		return
 	}
 
+	log.Println("branch", data.DefaultBranch)
 	if data.DefaultBranch == "" {
-		data.DefaultBranch = "main"
+		data.DefaultBranch = h.c.Repo.MainBranch
 	}
 
 	did := data.Did