Add Markdown Processing to Event Description (#158)

[jadekeegan]

This PR adds markdown processing to the event descriptions using installed marked and dompurify modules. marked is used to parse the event description and convert it to HTML, while dompurify is used to sanitize the produced HTML.

Developer Concerns

• Should we use Text instead of String for our event description to allow for more characters in the description? String is restricted to 255 I believe. (Didn't want to make this change yet as (I think) it would require a small migration)
• May need to edit global styles for things to ensure that colors/etc look good still!

[ajaygandecha]

@jadekeegan hey, since we have diverged significantly in production since the last commit in this PR, I am going to close this pull request. However, I will keep you on #407 and we can keep this branch on record for solving this problem in the future!

I created a new ticket #514 which includes more details!