Grammar directives

A directive rides a pattern in queries.scm: (pattern) @capture (#set! "<name>" "<value>"). One name, one setting per file. A capture.<name>.* directive must ride a pattern that binds @<name>. A directive not listed here fails at load. See captures.

directive	values	what it does
`selfNesting`	(none)	Every capture’s same-capture candidates nest (the grammar-wide form).
`attach.gap`	a whole number	A comment run attaches to the next definition across at most this many blank rows; 0 means the capture takes no attached run. Default 1.
`docstring.owner`	next \| enclosing	Who a docstring documents: the definition that follows it, or the one that contains it. Default enclosing.
`capture.<name>.definition`	true \| false	The capture is an element rules can target. A grammar’s own capture must declare it; shared captures are definitions by default.
`capture.<name>.opaque`	true \| false	A different-capture candidate strictly inside is implementation and produces no element.
`capture.<name>.selfNesting`	true \| false	Same-capture candidates nest: a nested one is an element of its own.
`capture.<name>.absorbTail`	a whole number	The largest same-capture wrapper tail, in bytes, that still reads as one element (a trailing `;`).
`capture.<name>.merge`	contiguous \| adjacent \| none	A run of same-capture nodes is one element. contiguous: a blank row or another element ends the run; adjacent: only another element ends it; none: no merging.