Getting a validation warning for markdeep script

```
./casual-effects.com/markdeep/latest/markdeep.min.js: FAILED
sha256sum: WARNING: 1 computed checksum did NOT match
DANGER: Validation failed for downloaded third-party code; tampered with?
```

It looks like this pulls the latest version, and validates against a checksum, so it will start failing any time a new markdeep is released. We should either pin the version, or stop validating the checksum. Pinning the version is the safer choice, but I suddenly realize this is volunteering me for a pretty tedious job constantly trying to stay up to date with security bugs and such in downstream libraries. That sucks.

Finde die Regel für den Download und die Prüfsummenvalidierung für casual-effects.com/markdeep/latest/markdeep.min.js. Überprüfe, wie die aktuelle URL und der erwartete sha256 definiert sind, und pinne dann die Artefaktversion und aktualisiere ihre Prüfsumme, damit die Validierung für die gepinnte Datei erfolgreich ist.

Vom Indexierungsmodell aus dem Issue-Text verfasst.