Improving text for transactional write

Signed-off-by: P K Navin Shrinivas <[email protected]>

content/en/docs/v3.5/tutorials/how-to-transactional-write.md

@@ -21,3 +21,28 @@ del user1
 failure requests (get, put, delete):
 put user1 good
 ```
+
+### Transaction for multiple writes
+
+A transaction is an atomic If/Then/Else construct over the key-value store. It provides a primitive for grouping requests together in atomic blocks (i.e., then/else) whose execution is guarded (i.e., if) based on the contents of the key-value store. Transactions can be used for protecting keys from unintended concurrent updates, building compare-and-swap operations, and developing higher-level concurrency control. However, modifications to the same key multiple times within a single transaction are forbidden.
+
+```shell
+etcdctl --endpoints=$ENDPOINTS put user1 bad
+
+etcdctl --endpoints=$ENDPOINTS txn --interactive
+compares:
+value("user1") = "bad"
+
+success requests (get, put, del):
+put user test
+put user2 testing3
+get user1
+
+failure requests (get, put, del):
+put user1 bad
+```
+
+<!--need to add gif showing the examples for multiple writes and failing when written to same key-->
+
+
+