Changing website files to reflect 2019 version of course

[James-S-Santangelo]

Updating DESCRIPTION, _site.yml, about.Rmd, and Index.Rmd

DESCRIPTION

• Changed Ahmed, Sara, and James to authors to reflect authorship on R course paper
• Added Zoë and Gigi (2019 TAs) as contributors

_site.yml

• Changes dates for lectures
• Removed references to all lectures beyond lec 05 and all assignment to prevent them from rendering on website. Will add lecture references once they are finalized with the current TAs.

about.Rmd

• Added Zoë and Gigi

Index.Rmd

• Changed instructors.
• Changed course coordinator from Ahmed to James
• Changed lead instructor from Asher to Ben
• Updated lecture dates in syllabus
• Updated Mark breakdown and assignment due dates

Note: Syllabus and assignments will be updated again following the first TA meeting when topics and instructors are finalised

[aays]

Looks great! I figure we could have a separate PR for any changes after the first instructor meeting.