Fix line break in docs imports (#11270)

It is just a straightforward docs fix.

docs/snippets/modules/agents/how_to/mrkl.mdx

@@ -1,5 +1,9 @@
 ```python
-from langchain.chains import LLMMathChain\nfrom langchain.llms import OpenAI\nfrom langchain.utilities import SerpAPIWrapper\nfrom langchain.utilities import SQLDatabase\nfrom langchain_experimental.sql import SQLDatabaseChain
+from langchain.chains import LLMMathChain
+from langchain.llms import OpenAI
+from langchain.utilities import SerpAPIWrapper
+from langchain.utilities import SQLDatabase
+from langchain_experimental.sql import SQLDatabaseChain
 from langchain.agents import initialize_agent, Tool
 from langchain.agents import AgentType
 ```