Update CHANGELOG.md

Merge pull request primer#911 from primer/release-13.0.2

Primer CSS 13.0.2

Merge pull request primer#905 from primer/release-13.0.1

Primer CSS 13.0.1

Merge pull request primer#887 from primer/release-13.0.0

Release 13.0.0

Merge pull request primer#878 from primer/release-12.7.0

Primer CSS 12.7.0

Merge pull request primer#874 from primer/release-12.6.2

Release 12.6.2

Merge pull request primer#872 from primer/release-12.6.1

Release 12.6.1

Merge pull request primer#854 from primer/release-12.6.0

Release 12.6.0

Merge pull request primer#832 from primer/release-12.5.0

Primer 12.5.0

Merge pull request primer#810 from primer/release-12.4.1

Release 12.4.1