Update README.md

README.md

@@ -2,4 +2,47 @@
 A general purpose Lua preprocessor and minifier.
 
 ## Building
-To build, either execute `luapreproc` or `luacomp` on src/init.lua
+To build, either execute `luapreproc` or `luacomp` on src/init.lua
+
+### luapreproc
+Execute `luapreproc init.lua ../luacomp.lua`
+
+### luacomp
+Execute `luacomp init.lua -xO ../luacomp.lua`
+
+***NOTE***: Do not use a minifier, it breaks argparse!
+
+## How-To
+
+### Merging Lua source files
+```lua
+-- myfile.lua
+local my_lib = {}
+
+function my_lib.hello_world()
+  print("Hello, world!")
+end
+```
+
+```lua
+-- main.lua
+--#include "my_file.lua"
+my_lib.hello_world()
+```
+
+### Getting enviroment variables
+```lua
+print("This was compiled in the shell "..$(SHELL))
+```
+
+### Macros
+```lua
+@[[function my_macro(a, b)]]
+print("Hello, @[{a}]. Your lucky number is @[{b}].")
+@[[end]]
+
+@[[my_macro("world", 7)]]
+@[[my_macro("user", 42)]]
+@[[my_macro("Earth", 0)]]
+@[[my_macro("Satna", 666)]]
+```