Consistent use of uppercase/lowercase for certain terms

This is a minor thing but host, instructor, introduction, helper, logistics, icebreaker, etc. terms are both used with the capital first letter and lowercase and we should make it consistent. I also feel that words such as 'Introduction' and 'Icebreaker' do not require capital first letter in the middle of the sentence in the same way we want to capitalise Instructor/Host/Helper roles.

Start by searching the repository for the listed terms and their capitalized and lowercase forms. Review each occurrence in context, applying the issue's distinction between role names and ordinary mid-sentence words; done means the relevant usage is consistent throughout the affected content.

Written by the indexing model from the issue text.