Generate a makefile config instead of a makefile with predefined
constants. This makes the build a bit more easier to modify. Also
improve the makefile and apply some suggestions from shellcheck. :)
Added:
- esv.d: reusable D interface to the ESV web API
- main.d: the main program
- Makefile
- README.md
- modified version of dini (dependency)
- man pages
- licenses