Improve logic in header partial
Improve logic in header partial

Use 'with' and 'not' to reduce redundancy.

Changes implemented upstream per my suggestion by
https://github.com/key-amb/hugo-theme-bootie-docs/commit/ead12f.

Signed-off-by: Ethan Madison <0a27e12d062ad71673d57f9c2799b207af316885@ethanmad.com>

UM-Fencing/club-theme,UM-Fencing/club-theme