Code metadata

`code_metadata`

Source and script files detected as Code (extension + optional shebang via Linguist):

Field	Meaning
`script_type`	Linguist language
`byte_count`, `line_count`	Size
`bom`	Byte order mark when present
`line_ending`	`lf`, `crlf`, `cr`, or `mixed`
`trailing_newline`, `max_line_length`, `blank_line_count`	Line shape
`indentation`	`spaces`, `tabs`, or `mixed` on first non-blank lines