feat(lint): apply defaultIgnoreDirectories to nested directories

[secustor]

Context

Currently vale will still lint directories like node_modules or .git folders, if the are not at the root directory.

Example cases could be:

• JS monorepo packages/foo/node_modules
• Git Worktree setup worktree-a/.git

Implementation

This PR changes ignore behaviour for defaultIgnoreDirectories from being the full path to being the name of lowest directory name.

[jdkato]

Thanks!