Merge pull request #161 from dgraph-io/aa-doc-pydgraph-D-2777

Docs (discuss feedback): fix incorrect statement about upsert blocks allowing one query and one mutation

Author: bucanero

README.md

@@ -45,7 +45,7 @@ pip install pydgraph
 
 ### Install Notes
 
-To avoid issues when adding composite credentials or when using client authorization, please install gRPC version 1.19.0: 
+To avoid issues when adding composite credentials or when using client authorization, please install gRPC version 1.19.0:
 
 ```sh
 pip install grpcio==1.19.0
@@ -300,10 +300,14 @@ txn.do_request(request)
 
 ### Running an Upsert: Query + Mutation
 
-The `txn.do_request` function allows you to run upserts consisting of one query and
-one mutation. Query variables could be defined and can then be used in the mutation.
+The `txn.do_request` function allows you to use upsert blocks. An upsert block
+contains one query block and one or more mutation blocks, so it lets you perform
+queries and mutations in a single request. Variables defined in the query block
+can be used in the mutation blocks using the `uid` and `val` functions
+implemented by DQL.
 
-To know more about upsert, we highly recommend going through the [mutations docs](https://docs.dgraph.io/mutations/#upsert-block).
+To learn more about upsert blocks, see the
+[Upsert Block documentation](https://dgraph.io/docs/mutations/upsert-block/).
 
 ```python
 query = """{