Adds files created moment-timezone-include webpack plugin to source control

[HarveyPeachey]

Resolves #N/A

Overall change: Adds files created from moment-timezone-include on webpack compilation to source control

Code changes:

• Adds src/app/legacy/psammead/moment-timezone-include/tz to source control
• Removes moment-timezone-include gitignore for tz
• Removes line in root gitignore for tz

---

• [x] I have assigned myself to this PR and the corresponding issues
• [x] I have added the cross-team label to this PR if it requires visibility across World Service teams
• [ ] I have assigned this PR to the Simorgh project
• [x] (BBC contributors only) This PR follows the repository use guidelines

Testing:

• [ ] Automated (jest and/or cypress) tests added (for new features) or updated (for existing features)
• [ ] If necessary, I have run the local E2E non-smoke tests relevant to my changes (CYPRESS_APP_ENV=local CYPRESS_SMOKE=false yarn test:e2e:interactive)
• [ ] This PR requires manual testing