Yamale schema validation for data set descriptions (#34)

* https://app.zenhub.com/workspaces/justice40-60993f6e05473d0010ec44e3/issues/usds/justice40-tool/40

data-roadmap/data_roadmap/data_set_descriptions/PM25.yaml

@@ -0,0 +1,35 @@
+name: Particulate Matter 2.5
+
+source: https://gaftp.epa.gov/EJSCREEN/
+
+relevance_to_environmental_justice: Particulate matter has a lot of adverse impacts
+  on health.
+
+data_formats: CSV/XLSX
+
+spatial_resolution: Census block group
+
+public_status: Public
+
+sponsor: EPA
+
+subjective_rating_of_data_quality: Medium Quality
+
+estimated_margin_of_error:
+
+known_data_quality_issues: Many PM 2.5 stations are known to be pretty far apart, so
+  averaging them can lead to data quality loss.
+
+geographic_coverage_percent:
+
+geographic_coverage_description:
+
+last_updated_date: 2017-01-01
+
+frequency_of_updates: Less than annually
+
+documentation: https://www.epa.gov/sites/production/files/2015-05/documents/ejscreen_technical_document_20150505.pdf#page=13
+
+data_can_go_in_cloud: True
+
+discussion: