fix favicon image on mindersec.dev

[manzil-infinity180]

Incorrect image/favicon path

https://github.com/mindersec/minder/blob/ea1db4a67a5020520346c440de820e200156e19f/docs/docusaurus.config.js#L36-L39

docs https://docusaurus.io/docs/api/docusaurus-config#favicon

[manzil-infinity180]

Here, we also need to change the link to the correct website link

[evankanderson]

Thanks! We recently moved the docs to docs.mindersec.dev, but I missed updating links (or putting in a forwarder yet).