[vec]please add speaker verification model description

[LeoMax-Xiong]

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Describe the bug
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To Reproduce
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2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
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** Environment (please complete the following information):**

• OS: [e.g. Ubuntu]
• GCC/G++ Version [e.g. 8.3]
• Python Version [e.g. 3.7]
• PaddlePaddle Version [e.g. 2.0.0]
• Model Version [e.g. 2.0.0]
• GPU/DRIVER Informationo [e.g. Tesla V100-SXM2-32GB/440.64.00]
• CUDA/CUDNN Version [e.g. cuda-10.2]
• MKL Version
• TensorRT Version

Additional context
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