In docs, don't show a "Functions" header if it's not going to have any contents

[nicolo-ribaudo]

https://jsr.io/@babel-test-6ae45912/runtime@0.0.1-8.0.0-alpha.15/doc/helpers/arrayWithHoles

This is admittedly a bit of a weird package, as it has no type definitions at all

It also has no exports: it was meant to have exports, but I messed up my publishing script so it ended up publishing as CJS, which from an ESM point of view has no exports. This is however not an unreasonable case, as you might have an actual module that has no exports: it's very common for polyfills.

JSR should not show the "Functions" header, as there are no functions exported by the package.