Refactor TOC code, move getting filter

## Pandoc filter to set the title of a document

- `src/coliverter/resources/pandoc-heading-to-title.lua`

- `src/coliverter/resources/pandoc/heading-to-title.lua`

  - Answer to: Set html title from the first header with pandoc

  - Author: johndoe (https://stackoverflow.com/users/2520247/johndoe)

  - URL: https://stackoverflow.com/a/76048743

from importlib import resources

from pathlib import Path

def get_filter(name: str) -> Path:

    with resources.path("coliverter.resources.pandoc", f"{name}.lua") as path:

        return path