Update docfx.json

Updating Redis cache search scope to join with the Powershell and CLI search scopes.

Author: JasonWHowell

docfx.json

@@ -401,6 +401,8 @@
       "searchScope": {
         "articles/azure-databricks/**/*.md": ["Azure","Azure Databricks"],
         "articles/azure-databricks/**/*.yml": ["Azure","Azure Databricks"],
+        "articles/cache/**/*.md": ["Azure","Cache for Redis"],
+        "articles/cache/**/*.yml": ["Azure","Cache for Redis"],
         "articles/cosmos-db/**/*.md": ["Azure","Azure Cosmos DB"],
         "articles/cosmos-db/**/*.yml": ["Azure","Azure Cosmos DB"],
         "articles/data-catalog/**/*.md": ["Azure","Azure Data Catalog"],