add new codeowner, update pull request template (GoogleCloudPlatform#4412)

Author: leahecole

.github/CODEOWNERS

@@ -22,6 +22,7 @@
 /composer/**/*.py                      @leahecole @GoogleCloudPlatform/python-samples-owners
 /compute/**/*.py                       @GoogleCloudPlatform/python-samples-owners
 /container_registry/**/*.py            @donmccasland @GoogleCloudPlatform/python-samples-owners
+/data-science-onramp/                  @coleleah @bradmiro @GoogleCloudPlatform/python-samples-owners
 /datacatalog/**/*.py                   @shollyman @GoogleCloudPlatform/python-samples-owners
 /dataflow/**/*.py                      @davidcavazos @GoogleCloudPlatform/python-samples-owners
 /datalabeling/**/*.py                  @sgreenberg @GoogleCloudPlatform/python-samples-owners

.github/PULL_REQUEST_TEMPLATE.md

@@ -12,3 +12,4 @@ Note: It's a good idea to open an issue first for discussion.
 - [ ] These samples need a new **API enabled** in testing projects to pass (let us know which ones)
 - [ ] These samples need a new/updated **env vars** in testing projects set to pass (let us know which ones)
 - [ ] Please **merge** this PR for me once it is approved.
+- [ ] This sample adds a new sample directory, and I updated the [CODEOWNERS file](https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/.github/CODEOWNERS) with the codeowners for this sample