Pocket modeling knife

##Action
https://youtu.be/k-VFDC3l3Wg

## Pocket modeling knife constructor
Inspired by https://countycomm.com

You can customize it due to your needs, starting from smallest protative version and up to pen-like version with storage for extra blades. Also avaiable caps with holes for keychain.

## Print reccomеndations
Prefered to pring blade_holder and blade_handle with 100% filling as this are most stressed parts.

## Mandatory parts
- blade_holder
- blade_handler
- middle

## Optional
- cap - _big cap w/o hole, covers the blade in closed position, and used as a handle in open_
- cap_small - _small cap for key-chain variant, required cap part to cover the blade_
- cap_hole - _cap with hole, same as cap, but with hole for another key-chain variant_