docs: fix subject-verb agreement in agent loop description (#3605)

Author: mshsheikh

docs/running_agents.md

@@ -263,7 +263,7 @@ There are four common ways to carry state into the next turn:
 
 Calling any of the run methods can result in one or more agents running (and hence one or more LLM calls), but it represents a single logical turn in a chat conversation. For example:
 
-1. User turn: user enter text
+1. User turn: user enters text
 2. Runner run: first agent calls LLM, runs tools, does a handoff to a second agent, second agent runs more tools, and then produces an output.
 
 At the end of the agent run, you can choose what to show to the user. For example, you might show the user every new item generated by the agents, or just the final output. Either way, the user might then ask a followup question, in which case you can call the run method again.