Update for Jira and GitHub

(cherry picked from commit a159696a2a19e343549b774710710d6468c296f3)
Update conference to DNNCon

(cherry picked from commit f03eacdea6d2f5fda4af6415045b37cd51a687e8)
Update sponsors

(cherry picked from commit a0e2909bba3c4ad06ea85de98225dbd69915ac4e)
Update Engage logo

(cherry picked from commit 1dac9e399484ed727aa0d0b464f4319ebb0ad6da)