Update FAQ.md (#1967)

* Update FAQ.md and README.md with FAQ links.

README.md

@@ -323,9 +323,10 @@ When you submit a pull request, a CLA-bot will automatically determine whether y
 This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/). For more information see the Code of [Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact opencode@microsoft.com with any additional questions or comments.
 
 After getting familiar with contribution agreements, you are ready to create your first PR =), follow the NNI developer tutorials to get start:
-* We recommend new contributors to start with ['good first issue'](https://github.com/Microsoft/nni/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22) or ['help-wanted'](https://github.com/microsoft/nni/issues?q=is%3Aopen+is%3Aissue+label%3A%22help+wanted%22), these issues are simple and easy to start.
+* We recommend new contributors to start with simple issues: ['good first issue'](https://github.com/Microsoft/nni/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22) or ['help-wanted'](https://github.com/microsoft/nni/issues?q=is%3Aopen+is%3Aissue+label%3A%22help+wanted%22).
 * [NNI developer environment installation tutorial](docs/en_US/Tutorial/SetupNniDeveloperEnvironment.md)
 * [How to debug](docs/en_US/Tutorial/HowToDebug.md)
+* If you have any questions on usage, review [FAQ](https://github.com/microsoft/nni/blob/master/docs/en_US/Tutorial/FAQ.md) first, if there are no relevant issues and answers to your question, try contact NNI dev team and users in [Gitter](https://gitter.im/Microsoft/nni?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) or [File an issue](https://github.com/microsoft/nni/issues/new/choose) on GitHub.
 * [Customize your own Tuner](docs/en_US/Tuner/CustomizeTuner.md)
 * [Implement customized TrainingService](docs/en_US/TrainingService/HowToImplementTrainingService.md)
 * [Implement a new NAS trainer on NNI](https://github.com/microsoft/nni/blob/master/docs/en_US/NAS/NasInterface.md#implement-a-new-nas-trainer-on-nni)

docs/en_US/Tutorial/FAQ.md

@@ -47,5 +47,9 @@ Probably it's a problem with your network config. Here is a checklist.
 ### NNI on Windows problems
 Please refer to [NNI on Windows](NniOnWindows.md)
 
+
+### More FAQ issues
+[NNI Issues with FAQ labels](https://github.com/microsoft/nni/labels/FAQ)
+
 ### Help us improve
 Please inquiry the problem in https://github.com/Microsoft/nni/issues to see whether there are other people already reported the problem, create a new one if there are no existing issues been created.