Support document writers

[na4zagin3]

Satyrographos needs to support document writers as well as library creators.

• [ ] satysfi subcommand to run SATySFi (https://github.com/na4zagin3/satyrographos/pull/137)
• [ ] build subcommand (https://github.com/na4zagin3/satyrographos/pull/194)
• Document buildfile
  • Lang 0.0.3 (#168)
  • [ ] New format type (#202)
  • [ ] Lint
  • util dep-make subcommand to extract dependency graphs
  • [X] .saty input support (#203)
  • [ ] Markdown input support (#205)
• Templates
  • [X] .saty with Makefile (#206)
  • [ ] .saty with OMake
• Autogen libraries
  • [ ] %today (#201)
• [ ] Library version lockdown file (https://github.com/na4zagin3/satyrographos/issues/98, https://github.com/na4zagin3/satyrographos/issues/83)
• [ ] Automatically download/install libraries (https://github.com/na4zagin3/satyrographos/issues/1)