Update the link of assessor tutorial in README.md (#730)

* Fix typo in README.Makefile.md

Fix typo in README.Makefile.md.

* Fix links in README.md

Fix links in README.md

* Update the link of assessor tutorial.

“docs/Customize_Assessor.md” is a better tutorial than “examples/assessors/README.md” for Customize Assessor.
The link of “Base-Assessor” in “examples/assessors/README.md” is not available.

README.md

@@ -189,7 +189,7 @@ You can use these commands to get more information about the experiment
 * [Try different tuners](docs/tuners.rst)
 * [Try different assessors](docs/assessors.rst)
 * [Implement a customized tuner](docs/Customize_Tuner.md)
-* [Implement a customized assessor](examples/assessors/README.md)
+* [Implement a customized assessor](docs/Customize_Assessor.md)
 * [Use Genetic Algorithm to find good model architectures for Reading Comprehension task](examples/trials/ga_squad/README.md)
 
 ## **Contribute**

zh_CN/README.md

@@ -200,7 +200,7 @@ NNI (Neural Network Intelligence) 是自动机器学习（AutoML）的工具包
 * [尝试不同的 Tuner](docs/tuners.rst)
 * [尝试不同的 Assessor](docs/assessors.rst)
 * [实现自定义 Tuner](docs/Customize_Tuner.md)
-* [实现自定义 Assessor](examples/assessors/README.md)
+* [实现自定义 Assessor](docs/Customize_Assessor.md)
 * [使用进化算法为阅读理解任务找到好模型](examples/trials/ga_squad/README.md)
 
 ## **贡献**