add doc

README.md

@@ -1,2 +1,78 @@
 # nix2lua
 
+This is a small but functional library that converts your nix configurations
+into lua format.
+
+This library was initially designed for my personal
+[neovim flake](https://git.pleshevski.ru/mynix/neovim).
+
+## Installation
+
+Add nix2lua as input to your flake.nix
+
+```nix
+{
+  inputs.nix2lua.url = "git+https://git.pleshevski.ru/mynix/nix2lua";
+  
+  outputs = { nix2lua }:
+    let
+      luaTable = nix2lua.lib.toLua {
+        foo = "bar";
+
+        nvimTree.settings = {
+          open_on_setup = true;
+          renderer = {
+            group_empty = true;
+            full_name = true;
+          };
+        };
+      };
+    in luaTable;
+}
+```
+
+## References
+
+`toLua expr`
+
+> Returns a string containing Lua representation of `expr`. Strings, integers,
+> floats, booleans, lists and sets are mapped to their Lua equivalents.
+>
+> Null will be skipped. This is useful when you want to use an optional value.
+> To render `nil` you should use the `mkLuaNil` function.
+>
+> ```nix
+> toLua { foo = "bar"; };
+> toLua [ 10 "foo" [ "bar" ] ];
+> ```
+
+`mkLuaNil expr`
+
+> Creates a type that will mapped by the `toLua` as `nil`
+>
+> ```nix
+> toLua mkLuaNil;
+> ```
+
+`mkLuaRaw expr`
+
+> Creates a type that instructs `toLua` not to change the passed expression
+> `expr`.
+>
+> ```nix
+> toLua (mkLuaRaw "require('bar').baz");
+> ```
+
+`mkNamedField name expr`
+
+> Creates a type that represents a named field in the lua table. This type
+> cannot exist outside of a list or set.
+>
+> This is usefull to create table with some named fields.
+>
+> ```nix
+> toLua [
+>   "foo"
+>   (mkNamedField "bar" "baz")
+> ];
+> ```