adding the links to all indexing materials

Author: negin513

workshops/scipy2023/README.md

@@ -63,7 +63,11 @@ Once your codespace is launched, the following happens:
 ```
 
 ```{dropdown} Indexing
+{doc}`../../fundamentals/02.1_indexing_Basic`
+
 {doc}`../../intermediate/indexing/advanced-indexing`
+
+{doc}`../../intermediate/indexing/boolean-masking-indexing`
 ```
 
 ```{dropdown} Computational Patterns