Fixed typo in Update Portainer-agent.md

Author: Noschvie

docs/Containers/Portainer-agent.md

@@ -5,15 +5,15 @@
 
 ## About
 
-The protainer agent is a great way to add a second docker instance to a existing portainer instance. this allows you to mananage multiple docker enviroments form one prortainer instance
+The portainer agent is a great way to add a second docker instance to an existing portainer instance. This allows you to manage multiple docker environments from one portainer instance.
 
 ## Adding to an existing instance
 
-When you want to add the the agent to an existing portianer instance. 
+When you want to add the agent to an existing portainer instance. 
 
 * You go to the endpoints tab.
 * Click on `Add endpoint`
 * Select Agent
 * Enter the name of the agent
 * Enter the url of the endpoint `ip-of-agent-instance:9001`
-* Click on add endpoint
+* Click on add endpoint