SKILL.md is read below the folder that holds skillDir, so the skill's own
folder is looked at too: never through a symbolic link at that folder or
below it, never waiting, and only when it is a regular file
(readFileOutsideLinks). A SKILL.md refused that way, or one that cannot
be loaded, is skipped with a warning.
Parameters
skillDir: string
Path to skill directory (should contain SKILL.md). It may
not be a symbolic link; the folder that holds it may.
Load a single skill from a directory.
SKILL.md is read below the folder that holds
skillDir, so the skill's own folder is looked at too: never through a symbolic link at that folder or below it, never waiting, and only when it is a regular file (readFileOutsideLinks). A SKILL.md refused that way, or one that cannot be loaded, is skipped with a warning.