Update chatwoot.md and add maybe cache on the nginx for all apps.

[uhlhosting]

Hi,

I am using for some time BTCPay and its options in testing, recently found some issues with Chatwoot, one of them is not serving any of the files with Cache-Headers in nginx, since nGinx is default server/proxy for all services this can be easily solved.

About the chatwoot.md docs from https://github.com/btcpayserver/btcpayserver-docker/blob/master/docs/chatwoot.md the last step: Go to chatwoot website at https://chatwoot.xpayserver.com and set up. this is not valid anymore. There is a weird redirection chain involved. Would be great to update it. Or remove it. If you need a testing version I can maybe provide one, let me know.

This is an example from GTMetrix, where I have used the widget to display chatwoot on one website: