Update slack message display

Display the build messages as an attachment in slack.

0.5.0

• Pass Slack message timestamp to GitHub workflow dispatch
• Make slack messages more compact

0.4.0

What's Changed

• trigger github e2e action if required annotations are present by @blunckr-aj in #9, requires a GITHUB_TOKEN secret

first test of github workflow triggering

0.4.test.0

first pass at adding github workflow triggering

v0.3.2

Fixes icon

0.3.1: Merge pull request #6 from atomicjolt/mp-update-icon

Update slack icon to use emoji

v0.3.0

Merge pull request #2 from atomicjolt/mp-initial

Initial import