[FEATURE] Custom Attachment Slots

[DarnHyena]

It would be quite handy to have such a feature for equippables that are out of the ordinary uses that would normally go into the
current existing slots of Head, Chest, Legs, Cape.

For example, perhaps someone has a mod that fully replaces the playable model, they could then make use of some sort of 'costume/skin' type of slot.

If someone wanted to make a mask, eyewear, or any other sort of accessory for the face, Mask, Eyes, Ears, and Mouth are another set of examples for slots.

Maybe could even be some additional slots along the rest of the body depending on how elaborate you want, or able, to get with such a feature.

Here's an example of an old mod someone made of such.
https://github.com/nearbear/ValheimBepinexMods/tree/main/CustomSlotItemLib
https://valheim.thunderstore.io/package/nearbear/WishboneSlot/