Falcon BYOC xgboost - first commit (#3982)

* Falcon BYOC xgboost - first commit

* Markdown fixes - dbl quote featurizer, add links to xgboost, sklearn

* rename request_body var to input_data in featurizer/code/inference.py

* Markdown fixes - renamed featurizer to preprocessor

* Markdown fixes for predictor, serial-inf-pipelines

* updated README.md, renamed inference.py to preprocessing.py

* updated images to reflect Dockerfile and script name

* Replace pickle.load with joblib.load, update Dockerfile

* update wsgi.py to import preprocessing.py as app

* updated s3 url for dataset to sagemaker-example-files-prod-REGION

* black-nb formatting on featurizer.ipynb

* grammar fixes

* add CI badges, download model from s3, end2end run fixes

* cleared notebook outputs

* commented out cells with curl commands

* test

* test

* test

---------

Co-authored-by: EC2 Default User <ec2-user@ip-172-16-30-98.us-west-2.compute.internal>
Co-authored-by: atqy <atqy@amazon.com>
Co-authored-by: atqy <95724753+atqy@users.noreply.github.com>