Add newberry/postcard-tag to PFE slugs

[zwolf]

zooniverse/Panoptes-Front-End#7506
zooniverse/static#446

How to Review

Helpful explanations that will make your reviewer happy:

• What Zooniverse project should my reviewer use to review UX?
• What user actions should my reviewer step through to review this PR?
• Which storybook stories should be reviewed?
• Are there plans for follow up PR’s to further fix this bug or develop this feature?

Checklist

PR Creator - Please cater the checklist to fit the review needed for your code changes.
PR Reviewer - Use the checklist during your review. Each point should be checkmarked or discussed before PR approval.

General

• Tests are passing locally and on Github
• Documentation is up to date and changelog has been updated if appropriate
• You can pnpm panic && pnpm bootstrap
• FEM works in all major desktop browsers: Firefox, Chrome, Edge, Safari (Use Browserstack account as needed)
• FEM works in a mobile browser

General UX

Example Staging Project: i-fancy-cats

• All pages of a FEM project load: Home Page, Classify Page, and About Pages
• Can submit a classification
• Can sign-in and sign-out
• The component is accessible
  • Can be used with a screen reader BBC guide to VoiceOver
  • Can be used from the keyboard WebAIM guide to keyboard testing
  • It is passing accessibility checks in the storybook

Bug Fix

• The PR creator has listed user actions to use when testing if bug is fixed
• The bug is fixed
• Unit tests are added or updated

New Feature

• The PR creator has listed user actions to use when testing the new feature
• Unit tests are included for the new feature
• A storybook story has been created or updated
  • Example of SlideTutorial component with docgen comments, and its story

Refactoring

• The PR creator has described the reason for refactoring
• The refactored component(s) continue to work as expected

Maintenance

• If not from dependabot, the PR creator has described the update (major, minor, or patch version, changelog)

Post-merge

• This PR adds translations keys to English dictionary(s). See guidance for pulling new keys to Lokalise here.