v0.3.0

• --cssv-key accepts col(n), the nth column counted from 1, whatever its name: for exports whose column names change, such as a header with the month in it, and for one of several columns that share a name. A quoted "col(2)" stays a name, and the host's key attribute takes names only (§9.1).
• parseKey() reads a --cssv-key value, and toHtml()'s key option also takes a column number.
• The README opens with an intro animation rendered from real tables.
• The README, llms.txt and the skill load the renderer from @0.3.