Add simpla-markdown

[madeleineostoja]

SimplaElements/simpla-markdown

Unfortunately only compatible with v1 spec polyfills, so will need to be held back until all elements are published as hybrids and we encourage use of the v1 polyfills. Which in turn is held up by is="" support shipping in the custom elements polyfill.

Also need to build proper demo, write README, and publish to webcomponents.org.

The element itself is ready to go - already used extensively on simpla.io, and very, very useful for any kind of complex content (eg: docs)

[bedeoverend]

I'm right in thinking that this is only compatible with v1 if you're wanting to edit in Shady DOM right? You can use it on v0 if you limit editing to just Chrome which has native v0 support?

[madeleineostoja]

Way too big a gotcha to justify adding to element catalogue now.