docs: use pipenv run instead of pipenv shell

Both work but pipenv shell can have side-effects

README.md

@@ -35,7 +35,6 @@ Subsequent requests to the client endpoint return the client_id but not the secr
 
 ```
 pipenv install  
-pipenv shell 
 ```
 
 ### Running 
@@ -46,10 +45,8 @@ pipenv shell
 
 #### API 
 
-In a `pipenv shell`
-
 ```
-python api.py 
+pipenv run python api.py 
 ```
 
 #### Create some clients 
@@ -58,24 +55,20 @@ python api.py
 
 #### Event bus 
 
-In a `pipenv shell` 
-
 ``` 
-python soar_bus.py
+pipenv run python soar_bus.py
 ```
 
 #### Send / Receive directly 
 
-In a `pipenv shell` 
-
 ```
 # Send a message 
-python client_send.py noc-c2-outbox 'soar.noc.slocum.something' from noc-c2
+pipenv run python client_send.py noc-c2-outbox 'soar.noc.slocum.something' from noc-c2
 ```
 
 ```
 # Receive messages  
-python client_read.py noc-sfmc-inbox
+pipenv run python client_read.py noc-sfmc-inbox
 ```
 
 #### Receive via API