Document how to allow blocked files

[rmccue]

By default, certain types of requests are blocked, but you might want to allow these through. For example, all requests for files starting with . are blocked, but /.well-known is part of several important protocols that you might want to handle.

These can be handled by adding a rule, but must be added using the regex-style match for specificity which could catch people out and can be hard to debug if you don't have the source.

eg (the ~ marks this as regex-style):

location ~ /\.well-known/webfinger {
	try_files $uri /index.php$is_args$args;
}

[roborourke]

Should we just bake that into the main nginx config?

[rmccue]

For .well-known? It's not that commonly used for the stuff we're doing (I was implementing ActivityPub), so I'd say only the general docs are needed.