add section links

Author: stephmarie17

source/fundamentals/transactions.txt

@@ -92,7 +92,7 @@ methods you can use to manage your transaction:
        | **Parameter**: ``TransactionBody<T> transactionBody``
 
 A ``ClientSession`` also has methods to retrieve session properties and modify mutable 
-session properties. View the :ref:`API Documentation` to learn more about these methods.
+session properties. View the `API Documentation`_ to learn more about these methods.
 
 Example
 -------
@@ -115,7 +115,7 @@ and commit a multi-document insert operation through the following steps:
 
 If you require more control over your transactions, you can use the ``startTransaction()``
 method. This method allows you to explicitly commit or abort the transaction and manually
-manage the transaction lifecycle. See :ref:`Methods`.
+manage the transaction lifecycle. See `Methods`_.
 
 Additional Information
 ----------------------