v2: Add accessibility attributes to layout tables

[joeworkman]

Carry-over from closed PR #114 by @andycoffey-uno.

Layout tables generated by Inky should include role="presentation" so screen readers don't interpret them as data tables. This is an important accessibility improvement.

Reference: https://www.w3.org/WAI/tutorials/tables/tips/

[joeworkman]

Addressed in Inky v2. All layout tables now include role="presentation" and decorative elements include aria-hidden="true".