Added AutoML team reviewers (#4144)

* Added CODEOWNERS file in the .github/ folder. This allows reviewers to review any changes in the machine learning repository

* Updated .github/CODEOWNERS with the team instead of individual reviewers

* Added AutoML team reviwers to files owned by AutoML team

* Added AutoML team reviwers to files owned by AutoML team

* Removed two files that don't exist for AutoML team in CODEOWNERS

Author: harshithapv

.github/CODEOWNERS

@@ -2,6 +2,10 @@
 # For more information on CODEOWNERS file see : https://help.github.com/en/articles/about-code-owners
 
 # For the entire repository 
-* @dotnet/mlnet-core
- 
+*	@dotnet/mlnet-core
 
+# Reviewers for files owned by AutoML team
+src/Microsoft.ML.AutoML	@dotnet/mlnet-automl
+test/Microsoft.ML.AutoML.Tests	@dotnet/mlnet-automl
+pkg/Microsoft.ML.AutoML	@dotnet/mlnet-automl
+docs/samples/Microsoft.ML.AutoML.Samples	@dotnet/mlnet-automl