Install Yarn and Git

[SzymonDzw]

The OS should be released with Yarn and Git already installed - would save some work for the developers.

[stsdc]

It was intentional to not install such tools on TurtleOS. Development is performed on developer's machine, not on Raspberry Pi. Building anything bigger than hello world takes a lot of time, so it is not performed on RaspberryPi.

[BlaQBobby]

Absolutely agree with @stsdc.