Add PR Template for Dataset Additions (#1383)

* initial add_dataset commit

* Rename .github/PULL_REQUEST-TEMPLATE/add_dataset.md to .github/PULL_REQUEST_TEMPLATE/add_dataset.md

* Update add_dataset.md

Author: WilliamHYZhang

.github/PULL_REQUEST_TEMPLATE/add_dataset.md

@@ -0,0 +1,20 @@
+# Add Dataset
+
+* Dataset Name: <name>
+* Issue Reference: <link>
+* `dataset_info.json` Gist: <link>
+  
+## Description
+
+<description>
+  
+## Checklist
+* [ ] Address all TODO's
+* [ ] Add alphabetized import to subdirectory's `__init__.py`
+* [ ] Run `download_and_prepare` successfully
+* [ ] Add checksums file
+* [ ] Properly cite in `BibTeX` format
+* [ ] Add passing test(s)
+* [ ] Add test data
+* [ ] Add data generation script (if applicable)
+* [ ] Lint code