Speed up compilation times for new projects

Best use case for gamejams and quick feature prototypes.

• install SCCACHE, a tool for caching and sharing prebuilt dependencies between multiple game projects (https://github.com/mozilla/sccache):

  cargo install sccache
  

• add these lines to the Cargo.toml:

  [package.metadata]
  # path to the sccache binary
  sccache_bin = "sccache.exe"
  # path to the sccache cache directory
  sccache_dir = "D:\\sccache"
  

From now on you will have to wait for full long engine build only once, for any other new game project you create, it will perform first compilation in matter of minute or less, not in minutes or more.