fix test.md

Author: huangli712

docs/src/man/test.md

@@ -1,3 +1,5 @@
 # Benchmark Tools
 
 [ACTest](https://github.com/huangli712/ACTest) is a benchmark tool for ACFlow. It can generate randomly a lot spectral functions and the corresponding Green's functions. These synthetic data can be used to benchmark the analytic continuation solvers as implemented in ACFlow.
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+More details could be found in [arXiv:2411.16412](https://arxiv.org/abs/2411.16412).