CodeFenceOpen
data class CodeFenceOpen(val fenceChar: Char, val fenceLength: Int, val indent: Int, val range: SourceRange) : Token
An opening code fence (` ``` ` or ~~~). @property fenceChar the fence character ('`' or '~') @property fenceLength the number of fence characters (≥ 3) @property indent the number of leading spaces (0–3)