Revert "exclude robots.txt from jekyll build. robots.txt should only reside on github repo serving pplaaf.link"
Revert "exclude robots.txt from jekyll build. robots.txt should only reside on github repo serving pplaaf.link"

This reverts commit b5925ace262e41465fe3ae703e7e59fa30f7828f.

jaysen/pplaaf,jaysen/pplaaf