added user resource and fixed some typos

examples/resources/gitea_user/resource.tf

@@ -0,0 +1,7 @@
+resource "gitea_user" "test" {
+  username             = "test"
+  login_name           = "test"
+  password             = "Geheim1!"
+  email                = "test@user.dev"
+  must_change_password = false
+}