How CpcSketch's CompressionData gets generated?

In code comment, I saw:

```
~/ocaml-4.03.0/bin/ocamlopt -o generateHuffmanCodes columnProbabilities.ml generateHuffmanCodes.ml
./generateHuffmanCodes > raw-encoding-tables.c
```

But I can't find the source of (`columnProbabilities.ml generateHuffmanCodes.ml`) anywhere.

Start with the code comment containing the ocamlopt command and inspect the references to columnProbabilities.ml, generateHuffmanCodes.ml, and raw-encoding-tables.c. Determine where the OCaml sources are kept or how the generated compression data is produced, then document that source and generation path in the project.

索引モデルが issue の本文から書いたものです。