feat(README): add SMI index as a Christmas special and update dataset details

README.md

@@ -10,12 +10,16 @@ tags:
   - finance
   - financial
   - stock-market
+  - stocks
   - OHLC
   - time-series
   - trading
   - equities
   - indices
   - historical-data
+  - stock-data
+  - market-data
+  - finance-data
 dataset_info:
   features:
     - name: symbol
@@ -79,7 +83,7 @@ size_categories:
 
 
 - More information about previous additions can be found further below in
-[The Growing Treasury](#️-the-growing-treasury)
+[The Growing Treasury](#️the-growing-treasury)
 
 </details>