Move EverlyAI python notebook to the right location (#11779)

Hi,

After submitting https://github.com/langchain-ai/langchain/pull/11357,
we realized that the notebooks are moved to a new location. Sending a
new PR to update the doc.

---------

Co-authored-by: everly-studio <127131037+everly-studio@users.noreply.github.com>

docs/docs/integrations/chat/index.mdx

@@ -22,6 +22,7 @@ AzureChatOpenAI|✅|✅|✅|✅
 BedrockChat|✅|❌|✅|❌
 ChatAnthropic|✅|✅|✅|✅
 ChatAnyscale|✅|✅|✅|✅
+ChatEverlyAI|✅|✅|✅|✅
 ChatFireworks|✅|✅|✅|✅
 ChatGooglePalm|✅|✅|❌|❌
 ChatJavelinAIGateway|✅|✅|❌|❌