Detail how to 'Tidy up issues' in issue template for release

[romaricpascal]

Add tasks to:

• ensure we use milestones to make it easier to find back what's shipped in a release
• verify that we documented our decisions, either on GitHub on in separate documents
• update the state of issues, both on the project board and on GitHub
• add any follow-up issues

[github-actions]

📋 Stats

File sizes

File	Size
dist/govuk-frontend-development.min.css	118.41 KiB
dist/govuk-frontend-development.min.js	42.7 KiB
packages/govuk-frontend/dist/govuk/all.bundle.js	92.79 KiB
packages/govuk-frontend/dist/govuk/all.bundle.mjs	87.12 KiB
packages/govuk-frontend/dist/govuk/all.mjs	1.25 KiB
packages/govuk-frontend/dist/govuk/govuk-frontend-component.mjs	1.74 KiB
packages/govuk-frontend/dist/govuk/govuk-frontend.min.css	118.4 KiB
packages/govuk-frontend/dist/govuk/govuk-frontend.min.js	42.69 KiB
packages/govuk-frontend/dist/govuk/i18n.mjs	5.55 KiB
packages/govuk-frontend/dist/govuk/init.mjs	7.13 KiB

Modules

File	Size (bundled)	Size (minified)
all.mjs	82.57 KiB	40.4 KiB
accordion.mjs	26.58 KiB	13.41 KiB
button.mjs	9.09 KiB	3.78 KiB
character-count.mjs	25.39 KiB	10.9 KiB
checkboxes.mjs	7.81 KiB	3.42 KiB
error-summary.mjs	10.99 KiB	4.54 KiB
exit-this-page.mjs	20.2 KiB	10.34 KiB
header.mjs	6.46 KiB	3.22 KiB
notification-banner.mjs	9.35 KiB	3.7 KiB
password-input.mjs	18.24 KiB	8.33 KiB
radios.mjs	6.81 KiB	2.98 KiB
service-navigation.mjs	6.44 KiB	3.26 KiB
skip-link.mjs	6.4 KiB	2.76 KiB
tabs.mjs	12.04 KiB	6.67 KiB

View stats and visualisations on the review app

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Action run for 14de4bc

[owenatgov]

LGTM 💪🏻

I've made some stylistic suggestions but nothing necessary. I'll leave it up to you if you think these are worth doing or not.