feat(model): add markdown block

[zimeg]

This PR adds the markdown block.

Reviewers

The following code snippets can post markdown messages:

import com.slack.api.model.block.Blocks.*;
import static com.slack.api.model.block.Blocks.*;

var markdownBlock = MarkdownBlock.builder()
    .text("**this is bold**")
    .build();
var response = slack.methods().chatPostMessage(r -> r.token(token).blocks(asBlocks(markdownBlock)).channel("C0123456789"));

var response2 = slack.methods().chatPostMessage(r -> r.token(token).blocks(asBlocks(markdown(m -> m.text("**epic**")))).channel("C0123456789"));

Category

• slack-api-model (Slack API Data Models)

Requirements

Please read the Contributing guidelines and Code of Conduct before creating this issue or pull request. By submitting, you agree to those rules.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 73.07%. Comparing base (9504d94) to head (b4c9d4c).

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #1521      +/-   ##
============================================
+ Coverage     73.02%   73.07%   +0.04%     
- Complexity     4399     4403       +4     
============================================
  Files           475      475              
  Lines         14266    14268       +2     
  Branches       1452     1452              
============================================
+ Hits          10418    10426       +8     
+ Misses         2987     2981       -6     
  Partials        861      861              

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[WilliamBergamin]

LGTM

[mwbrooks]

☕ @zimeg is becoming a Java guru! Thanks for remembering Java and adding the Markdown block!