AO3-7519 Update browser page title when creating an AO3 News Post

[99patricia]

Pull Request Checklist

• Have you read "How to write the perfect pull request"?
• Have you read the contributing guidelines?
• Have you added tests for any changed functionality?
• Have you added the Jira issue number
  as the first thing in your pull request title (e.g. AO3-1234 Fix thing)
• Do you have fewer than 5 pull requests already open? If not, please wait
  until they are reviewed and merged before creating new pull requests.

Issue

https://otwarchive.atlassian.net/browse/AO3-7519

Purpose

What does this PR do?

• Updates the locale config to contain the string "New AO3 News Post" for both page_title and page_heading for new ao3 news posts.
• Changes the browser page title to "New AO3 News Post | Archive of Our Own (or Example Archive)" when creating an AO3 News post.

Testing Instructions

How can the Archive's QA team verify that this is working as you intended?

• Log in as admin that can create news posts
• Navigate to Admin Posts > Post AO3 News
• The browser page title should now say "New AO3 News Post | Archive of Our Own (or Example Archive)"

Credit

Name: 99patricia (Patricia Zafra)
Pronouns: she/her

[marcus8448]

Hi, 99patricia!

Thanks so much for this pull request. Someone will be along to review it soon.

We've updated the Jira issue status to In Review so no one mistakenly creates a duplicate pull request. If you'd like the ability to comment on, assign, and transition issues in the future, you're welcome to create a Jira account! It makes things a bit easier for us on the organizational side if the Full Name on your Jira account either closely matches the name you'd like us to credit in the release notes or includes it in parentheses, e.g. "Nickname (CREDIT NAME)."

Once you've done that (or if you've already done it -- Jira has been unreliable about showing us new accounts in the admin panel lately), you can either reply here or send an email to otw-coders@transformativeworks.org with your account name and email address and we'll set up the permissions for you.

Thanks again for contributing! If you have any questions, you can contact us at the same email address listed above.