fix: return early if click targets element outside of root node

[m90]

This is related to choojs/choo#704

It looks like clicks outside the given root node would still be handled as the check of

nanohref/index.js

Line 22 in 80c11c4

if (!node || node === root) return

would never apply until the traversal has reached an anchor element.

Two questions/concerns from my side:

• Does Node.contains align with the supported browser range?
• In (the unlikely) case of root being an anchor element itself, a click on this element would also be skipped right now. This is the case with and without the fix, yet I am not sure if this is considered ok or should be fixed?