Polish up the event for the block directory

[ajlende]

• Rename jetpack to a8c
• Update image replace flow
• Add translation domain
• Final layout tweaks
• Add Event Block resources
  • Block directory block.json file
  • Tagline/Description copy
  • Plugin Assets

Bundle: a8c-event.zip

[ajlende]

@jasmussen I've wrapped up all the changes that I wanted to make. Can you help me with some plugin assets for the directory?

[jasmussen]

Hi Alex, lovely! If you feel this branch is solid, you can go ahead and merge it.

I'd like to make a few small visual changes -- a new G2 icon and other small things. I meant to get to that today, but due to unforeseen circumstance I have to jump to some toddler duty in a moment. So I'll probably get to some of this work tomorrow instead, at which point I'll also fix up the block directory assets.