🐛 resolves #310 fix Kroki on Firefox (#311)

* resolves #310 fix Kroki on Firefox

- Upgrade to asciidoctor-kroki v0.3.0
** Catch all exceptions when reading a file (because Firefox does not allow to read file from file:// protocol for security reasons)
** Remove rusha from the bundle (because for whatever reason, it does not work on Firefox)
- Load kroki.js before the renderer.js (order matters on Firefox)

* Upgrade Kroki extension to 0.4.0

* Forcibly remove the kroki-fetch-diagram attribute

Because this feature is not supported in a browser environment.

app/js/renderer.js

@@ -336,6 +336,8 @@ window.MathJax = {
     if (attributesQueryParameters.length > 0) {
       Array.prototype.push.apply(attributes, attributesQueryParameters)
     }
+    // Forcibly remove the "kroki-fetch-diagram" attribute because this feature is not supported in a browser environment.
+    attributes.push('kroki-fetch-diagram!')
     const registry = processor.Extensions.create()
     if (settings.krokiEnabled) {
       AsciidoctorKroki.register(registry, {