Update release instruction for updating the changelog

[romaricpascal]

• Add step to make sure the changelog matches the drafted release notes
• Simplify the insertion of the new heading (no need to replace 'Unreleased' and then add it back when we can just add a new heading)

[github-actions[bot]]

:clipboard: Stats

File sizes

File	Size
dist/govuk-frontend-development.min.css	112.61 KiB
dist/govuk-frontend-development.min.js	41.83 KiB
packages/govuk-frontend/dist/govuk/all.bundle.js	87.33 KiB
packages/govuk-frontend/dist/govuk/all.bundle.mjs	82.03 KiB
packages/govuk-frontend/dist/govuk/all.mjs	981 B
packages/govuk-frontend/dist/govuk/govuk-frontend-component.mjs	359 B
packages/govuk-frontend/dist/govuk/govuk-frontend.min.css	112.6 KiB
packages/govuk-frontend/dist/govuk/govuk-frontend.min.js	41.82 KiB
packages/govuk-frontend/dist/govuk/i18n.mjs	5.55 KiB
packages/govuk-frontend/dist/govuk/init.mjs	4.86 KiB

Modules

File	Size (bundled)	Size (minified)
all.mjs	79.16 KiB	39.79 KiB
accordion.mjs	23.5 KiB	12.39 KiB
button.mjs	5.98 KiB	2.69 KiB
character-count.mjs	22.4 KiB	9.92 KiB
checkboxes.mjs	5.83 KiB	2.83 KiB
error-summary.mjs	7.89 KiB	3.46 KiB
exit-this-page.mjs	17.1 KiB	9.26 KiB
header.mjs	4.46 KiB	2.6 KiB
notification-banner.mjs	6.26 KiB	2.62 KiB
password-input.mjs	15.15 KiB	7.25 KiB
radios.mjs	4.83 KiB	2.38 KiB
skip-link.mjs	4.39 KiB	2.18 KiB
tabs.mjs	10.05 KiB	6.06 KiB

View stats and visualisations on the review app

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