feat: update changelog.md file to generate release summary

[adpare]

The updated code enables the user to display a release summary between major and minor releases of ATT&CK.
To run -
For major release -

OUT=output/v17.1-v18.0
NEW=attack-releases/stix-2.0/v18.0
OLD=attack-releases/stix-2.0/v17.1

diff_stix -v \
  --old "$OLD" \
  --new "$NEW" \
  --show-key \
  --contributors \
  --html-file-detailed "$OUT/changelog-detailed.html" \
  --markdown-file "$OUT/changelog.md" \
  --json-file "$OUT/changelog.json" \
  --layers "$OUT/layer-enterprise.json" "$OUT/layer-mobile.json" "$OUT/layer-ics.json" \
  --release-summary \
  --release-summary-version v18 \
  --release-summary-data-version 18.0 \
  --release-summary-changelog-prefix /docs/changelogs

For minor release -

OLD=attack-releases/stix-2.0/v18.0
NEW=attack-releases/stix-2.0/v18.1
OUT=output/v18.0-v18.1

diff_stix -v \
  --old "$OLD" \
  --new "$NEW" \
  --show-key \
  --contributors \
  --html-file-detailed "$OUT/changelog-detailed.html" \
  --markdown-file "$OUT/changelog.md" \
  --json-file "$OUT/changelog.json" \
  --layers "$OUT/layer-enterprise.json" "$OUT/layer-mobile.json" "$OUT/layer-ics.json" \
  --release-summary \
  --release-summary-version v18 \
  --release-summary-data-version 18.0 \
  --release-summary-data-version 18.1 \
  --release-summary-changelog 17.1-18.0 \
  --release-summary-changelog 18.0-18.1 \
  --release-summary-changelog-prefix /docs/changelogs

[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud