cleaned up examples folder a bit (aws#97)

* cleaned up examples folder a bit

* pre-commit modifications

* Update examples/mxnet/README.md

* Update examples/mxnet/README.md

* fixed mxnet tests

* Added xgboost readme back to examples folder

Author: ddavydenko

examples/mxnet/README.md

@@ -1,2 +1,22 @@
-## Example Notebooks
+# Examples
+## Example notebooks
 Please refer to the example notebooks in [Amazon SageMaker Examples repository](https://github.com/awslabs/amazon-sagemaker-examples/tree/master/sagemaker-debugger)
+
+## Example scripts
+The above notebooks come with example scripts which can be used through SageMaker. Some more example scripts are here in [scripts/](scripts/)
+
+## Example configurations for saving tensors through [SageMaker Python SDK](https://github.com/aws/sagemaker-python-sdk)
+Example configurations for saving tensors through the hook are available at [docs/sagemaker.md](../docs/sagemaker.md)
+
+## Example configurations for running rules through [SageMaker Python SDK](https://github.com/aws/sagemaker-python-sdk)
+Example configurations for saving tensors through the hook are available at [docs/sagemaker.md](../docs/sagemaker.md)
+
+## Example for running rule locally
+
+```
+from smdebug.rules import invoke_rule
+from smdebug.trials import create_trial
+trial = create_trial('s3://bucket/prefix')
+rule_obj = CustomRule(trial, param=value)
+invoke_rule(rule_obj, start_step=0, end_step=10)
+```