frontmatter 0.3.0

• format_front_matter() and write_front_matter() now infer the delimiter
  automatically when delimiter = NULL (the new default). If x was returned
  by parse_front_matter() or read_front_matter(), the original fence style
  is preserved; otherwise write_front_matter() falls back to the file
  extension of path, and finally to "yaml" (#8).

• Added support for shebang lines (#!) at the start of files. When a file
  begins with a shebang, the parser now recognizes front matter in
  comment-wrapped formats (# ---, #' ---) and PEP 723 (# /// script)
  immediately following the shebang (with zero or one blank lines in between).
  The shebang line is included in the returned body. format_front_matter()
  and write_front_matter() also move a leading shebang line above the front
  matter block when writing (#5).

• Added SQL front matter support with two comment styles: line comments
  (-- ---/-- +++) and block comments in compact (/* --- ... --- */) and
  expanded (/* + --- ... --- + */) forms. Six new delimiter shortcuts
  are available for write_front_matter(): yaml_sql_line,
  toml_sql_line, yaml_sql_block_compact, toml_sql_block_compact,
  yaml_sql_block_expanded, and toml_sql_block_expanded (#4).