Soft ring for soft release

This is a ring for a slackline soft-release to make it compatible with soft shackles. This part is designed around the [Equilibrium Soft Release Lite](https://www.slackshop.cz/en/custom-sewing/147-351-povolovak-lite.html#/166-length-6_m). The design might require some tinkering (increase the x and y scale of the "soft ring w slot") to make it work for other soft releases.

This part should never be used as a connector. Only as a "thimble" where it is backed up totally by the webbing/soft shackle

This part makes detensioning a soft release on soft shackles much easier, and reduces abrasion on the textile parts to increase their life.