fix: newline spacing after toc insert

chore: bump to 0.4.1

feat: enable optional toc heading

feat: exclude headings when ignore comment is provided

closes #1

bug: handle hash sign inside code blocks

fixes #2

refactor: update function names, cleanup library exports

feat: handle braces in header text

feat: handle backticks, double, single quotes

feat: add optional out flag, simplify write step

feat: add custom usage