[Gulliby]

Requested by gulliby

Before

A file without the <!-- toc --> / <!-- tocstop --> markers was an error, so the first table of contents of a new README had to be started by hand.

After

mdtoc --insert FILE adds the marker pair directly after the first level-1 ATX heading outside code fences (or at the start of the file when there is none) and then generates the entries. Files that already have markers are refreshed as before, so the command is safe to repeat; a file with only one marker is still an error. --insert cannot be combined with --check or --print.

bun run src/cli.ts --insert NOTES.md

# Guide
<!-- toc -->
- [Guide](#guide)
  - [Installation](#installation)
  - [Usage](#usage)
<!-- tocstop -->

## Installation

## Usage

How

• src/toc.ts: new exported insertMarkers; the fence scanning is shared with extractHeadings.
• src/cli.ts: the --insert option, its two conflicts, the usage text and the call.
• tests/insert.test.ts: new tests (158 tests pass in all); tests/print.test.ts only has the usage line updated.
• README.md: option row, "Add the markers" section, updated missing-markers sentence.