convert presentations to markdown

[kcranston]

Repos that need changing:

• rr-literate-programming (@hlapp)
• organization-1
• publication ( @tracykteal )

[mine-cetinkaya-rundel]

I'm working on organization-1/file naming slides + organization

[hlapp]

Conversion for Literate Programming lesson is in Reproducible-Science-Curriculum/rr-literate-programming#6.