Deleting cache directory as a troubleshooting effort

Might be worth mentioning somewhere that one possible way to debug is to delete the `.contentlayer` directory and restart the server. But ideally users would also log issues along the way.

No documentation file or test is named. Start by locating the website's troubleshooting guidance, then add the note about deleting `.contentlayer` and restarting the server, along with the suggestion to log issues encountered. Done means users can find this troubleshooting step in the documentation.

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