Fix copy-paste errors in convert.txt.

Author: dylankerr-bis

source/reference/operator/aggregation/convert.txt

@@ -69,12 +69,12 @@ Definition
 
              * - "double"
                - 1
-               - For more information on the conversion to boolean, see
+               - For more information on the conversion to double, see
                  :ref:`convert-to-double`.
 
              * - "string"
                - 2
-               - For more information on the conversion to boolean, see
+               - For more information on the conversion to string, see
                  :ref:`convert-to-string`.
 
              * - "objectId"
@@ -107,7 +107,7 @@ Definition
 
              * - "decimal"
                - 19
-               - For more information on the conversion to long, see
+               - For more information on the conversion to decimal, see
                  :ref:`convert-to-decimal`.
 
       * - ``onError``