Make env dir and move each cde into the dir

[Toraja]

Summary

• Each environment (go, rust etc) is located at the project root and it isn't very neat
• Move those environments into env directory (or other name)

Concern

• It might be difficult to integrate with lcde with current way which does complicated stuff in Makefile

[Toraja]

Solution

• Move each environment into env dir
• Move current localise symlink into env dir and it should point to <lcde root>/env

[Toraja]

This will be unnecessary due to #30