Other/Misc Content corrections and refresh on the landing and talk to us pages

[justinmacnair]

Summary

1. Links to Discord have been swapped for the new Slack channel and the broken link to the Weather demo is fixed
2. I removed the contact/discord channel calls to action on the Request a Demo page, which now links to the Medium blog as a place for interested parties to stay up to date. No nurture/follow up actions required.
3. The secondary call to action in the hero was swapped from Request a Demo to Try the Quickstart to better target developers
4. Added a “Past Events” section with links to KubeCon EU recordings [please let me know if there are others to include]
5. Added a “From the Blog” section with the latest 2 articles. I can set up a GitHub action to check for new articles on a cadence, but with our current publishing frequency I think manual updates are fine.

Related issue(s)

#64 #63

(Optional) Testing Instructions

Fixes #