Adding example problem to T2T documentation
Adding example problem to T2T documentation

PiperOrigin-RevId: 166912906

rsepassi/tensor2tensor,tensorflow/tensor2tensor,tensorflow/tensor2tensor,rsepassi/tensor2tensor,rsepassi/tensor2tensor,vthorsteinsson/tensor2tensor,rsepassi/tensor2tensor,tensorflow/tensor2tensor,waterblue13/tensor2tensor,tensorflow/tensor2tensor,vthorsteinsson/tensor2tensor,vthorsteinsson/tensor2tensor,tensorflow/tensor2tensor,waterblue13/tensor2tensor,vthorsteinsson/tensor2tensor,waterblue13/tensor2tensor