replaced <acronym> with <abbr> for HTML5. (#63)
replaced <acronym> with <abbr> for HTML5. (#63)

* replaced <acronym> with <abbr> for HTML5.
* fixed typo.

Co-authored-by: Christoph M. Becker <4fb47cf3e4d2e365399bbe05f5be691f4b0e72fe@gmx.de>
php/phd,php/phd