initial readme instructions

README.md

@@ -1,8 +1,54 @@
+# Pgn to Tex
+
+## Install
+
+- Install the Opam package with:
+  `opam install pgn_to_tex`
+- Reference `pgn_to_tex` in the libraries stanza in the relevant dune file
+
+## Usage
+
+```ocaml
+open Pgn_logic
+
+let diagrams_json_stringified = {| [{"ply":1,"fen":"rnbqkbnr/pppppppp/8/8/3P4/8/PPP1PPPP/RNBQKBNR b KQkq - 0 1"},{"ply":2,"fen":"rnbqkbnr/ppp1pppp/8/3p4/3P4/8/PPP1PPPP/RNBQKBNR w KQkq - 0 2"}] |}
+let diagram_data = Pgn2tex.parse_diagrams_json diagrams_json_stringified
+
+let game_tex = Pgn2tex.to_tex pgn ~diagram_data ~clock:false
+```
+
+This will return a LaTex markdown representation of the PGN file along with chess board diagrams at the specified ply. Clock times can be rendered for both sides if you pass `~clock:true` to the `to_tex` function.
+
+Latex preample and document setup markdown is not included in the output. You will need to add something similar to below around the `game_tex` output to create a valid document:
+
+```
+\begin{document}
+\begin{multicols}{2}
+game_tex goes here
+\end{multicols}
+\end{document}
+```
+
+## Compile a JavaScript version of the library
+
+With the library installed, you can compile the code to JavaScript by running:
+
+```
+make build
+```
+
+This will generate the JavaScript file at `_build/default/bin/main.bc.js`
+
+This JavaScript file is minified and in CJS format, working in both Node and in the browser.
+
+A single function `to_tex` is exposed, accepting the same arguments as the main library.
+
 ## Dependencies
 
 - dune
 - sedlex
 - menhir
+- yojson
 - js_of_ocaml-compiler
 - ocamlformat
 - ocaml-lsp-server