Adds a GitHub Action to validate RSIs (#3587)

* Validate RSIs

* Fix the JSON

* Example invalid RSI

* Revert "Example invalid RSI"

This reverts commit 1905bc9d2c275818db88cd8b643e2646f70b68a1.

* Fixes an invalid identifier to show that it works on valid RSIs

* Update .github/workflows/validate-rsis.yml

.github/workflows/validate-rsis.yml

@@ -0,0 +1,15 @@
+name: RSI Validator
+
+on: [push, pull_request]
+jobs:
+  validate_rsis:
+    name: Validate RSIs
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Parse files
+        uses: snapcart/json-schema-validator@v1.0.0
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          json_schema: .github/rsi-schema.json
+          json_path_pattern: .*meta.json$