add commands to Makefile: init, vendor, install

[justgook]

It would be nice to extend functionality of main makefile, to make onboarding much easier, by adding few commands (i could create also PR, for some part of that):

1. init-_TOOL_ - init new game or add configuration for specific tool in current directory, where tool could be one of:
   1. hello - inits basic game template - sample/basic/hello-worldlike
   2. image - same as previous only for image
   3. sonic - creates minimalistic platformer game (what other more canonical platformer-ga exists in MD)
   4. ……… -your submission???
   5. vscode - add vscode configs
   6. make - add Makefile, that have default commands, release, debug, clean
   7. git - init git repo, setup .gitignore, git-lfs
   8. github - add github template with enabled gh-actions pipelines to build game on commit
2. vendor - same as go vendor, create folder vendor in current game directory, put there current sources of sgdk, and use those to compile libmd.a, and game it self, from those sources.
3. install/update - copies sgdk to global scope of OS, and registers sgdk command globally, so You can call sgdk release from any floder.

[justgook]

and looks like andwn/marsdev is already lot of work done