docs(merge): fix formatting

[Splaktar]

PR Checklist

Please check that your PR fulfills the following requirements:

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[x] Documentation content changes
[ ] Infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

The header formatting is broken due to a change in GitHub Markdown formatting.

Issue Number:
N/A

What is the new behavior?

The headers are displayed properly.

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

N/A

[jelbourn]

LGTM