Add pa-ur locale (Punjabi Shahmukhi - Urdu script)

We already support `pa`, Punjabi Gurmukhi, a language used in Punjab,
India. This is to add `pa-ur`, Punjabi Shahmukhi, a language used in
Punjab, Pakistan, that uses the Urdu script.

More information on the two languages can be found on this Wikipedia
page: https://en.wikipedia.org/wiki/Punjabi_language

The reason `pa-ur` was chosen as locale code is that `pa` is the
language code for Punjabi and `ur` is the script subtag for Urdu. More
information on this can be found on this Mozilla developer docs page:
https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/lang#Language_tag_syntax

Docs followed: https://docs.publishing.service.gov.uk/manual/add-translation-whitehall.html

Zendesk ticket: https://govuk.zendesk.com/agent/tickets/4371686

Related PRs:
- alphagov/whitehall#5915
- https://github.com/alphagov/government-frontend/pull/1942/commits
- alphagov/govuk-content-schemas#1034
- alphagov/content-store#791
- alphagov/publishing-api#1883

config/application.rb

@@ -75,6 +75,7 @@ class Application < Rails::Application
       no
       nl
       pa
+      pa-ur
       pl
       ps
       pt

config/locales/en.yml

@@ -102,6 +102,7 @@ en:
     nl: Dutch
     "no": Norwegian
     pa: Punjabi
+    pa-ur: Punjabi Shahmukhi
     pl: Polish
     ps: Pashto
     pt: Portuguese

config/locales/pa-ur.yml

@@ -0,0 +1,290 @@
+pa-ur:
+  content_item:
+    schema_name:
+      aaib_report:
+        one:
+        other:
+      announcement:
+        one:
+        other:
+      asylum_support_decision:
+        one:
+        other:
+      authored_article:
+        one:
+        other:
+      business_finance_support_scheme:
+        one:
+        other:
+      case_study:
+        one:
+        other:
+      closed_consultation:
+        one:
+        other:
+      cma_case:
+        one:
+        other:
+      coming_soon:
+        one:
+        other:
+      consultation:
+        one:
+        other:
+      consultation_outcome:
+        one:
+        other:
+      corporate_information_page:
+        one:
+        other:
+      corporate_report:
+        one:
+        other:
+      correspondence:
+        one:
+        other:
+      countryside_stewardship_grant:
+        one:
+        other:
+      decision:
+        one:
+        other:
+      detailed_guide:
+        one:
+        other:
+      dfid_research_output:
+        one:
+        other:
+      document_collection:
+        one:
+        other:
+      draft_text:
+        one:
+        other:
+      drug_safety_update:
+        one:
+        other:
+      employment_appeal_tribunal_decision:
+        one:
+        other:
+      employment_tribunal_decision:
+        one:
+        other:
+      esi_fund:
+        one:
+        other:
+      fatality_notice:
+        one:
+        other:
+      foi_release:
+        one:
+        other:
+      form:
+        one:
+        other:
+      government_response:
+        one:
+        other:
+      guidance:
+        one:
+        other:
+      impact_assessment:
+        one:
+        other:
+      imported:
+        one:
+        other:
+      independent_report:
+        one:
+        other:
+      international_development_fund:
+        one:
+        other:
+      international_treaty:
+        one:
+        other:
+      maib_report:
+        one:
+        other:
+      map:
+        one:
+        other:
+      medical_safety_alert:
+        one:
+        other:
+      national:
+        one:
+        other:
+      national_statistics:
+        one:
+        other:
+      national_statistics_announcement:
+        one:
+        other:
+      news_article:
+        one:
+        other:
+      news_story:
+        one:
+        other:
+      notice:
+        one:
+        other:
+      official:
+        one:
+        other:
+      official_statistics:
+        one:
+        other:
+      official_statistics_announcement:
+        one:
+        other:
+      open_consultation:
+        one:
+        other:
+      oral_statement:
+        one:
+        other:
+      policy:
+        one:
+        other:
+      policy_paper:
+        one:
+        other:
+      press_release:
+        one:
+        other:
+      promotional:
+        one:
+        other:
+      publication:
+        one:
+        other:
+      raib_report:
+        one:
+        other:
+      regulation:
+        one:
+        other:
+      research:
+        one:
+        other:
+      residential_property_tribunal_decision:
+        one:
+        other:
+      service_sign_in:
+        one:
+        other:
+      service_standard_report:
+        one:
+        other:
+      speaking_notes:
+        one:
+        other:
+      speech:
+        one:
+        other:
+      statement_to_parliament:
+        one:
+        other:
+      statistical_data_set:
+        one:
+        other:
+      statistics_announcement:
+        one:
+        other:
+      statutory_guidance:
+        one:
+        other:
+      take_part:
+        one:
+        other:
+      tax_tribunal_decision:
+        one:
+        other:
+      transcript:
+        one:
+        other:
+      transparency:
+        one:
+        other:
+      utaac_decision:
+        one:
+        other:
+      world_location_news_article:
+        one:
+        other:
+      world_news_story:
+        one:
+        other:
+      written_statement:
+        one:
+        other:
+    contents:
+    metadata:
+      published:
+      updated:
+  publication:
+    documents:
+      one:
+      other:
+    details:
+  common:
+    last_updated:
+  components:
+    figure:
+      image_credit:
+    published_dates:
+      hide_all_updates:
+      last_updated:
+      published:
+      see_all_updates:
+      show_all_updates:
+    publisher_metadata:
+      collections:
+      from:
+      hide_all:
+      show_all:
+    related_navigation:
+      collections:
+      external_links:
+      policies:
+      publishers:
+      related_content:
+      related_guides:
+      statistical_data_sets:
+      topical_events:
+      topics:
+      world_locations:
+    share_links:
+      share_this_page:
+  corporate_information_page:
+    about_our_services_html:
+    corporate_information:
+    personal_information_charter_html:
+    publication_scheme_html:
+    social_media_use_html:
+    welsh_language_scheme_html:
+  detailed_guide:
+    related_guides:
+    related_mainstream_content:
+  language_names:
+    pa-ur: پن٘جابی
+  multi_page:
+    next_page:
+    previous_page:
+    print_entire_guide:
+  service_sign_in:
+    continue:
+    error:
+      option:
+      title:
+  time:
+    formats:
+      short_ordinal:
+  travel_advice:
+    alert_status:
+      avoid_all_but_essential_travel_to_parts:
+      avoid_all_but_essential_travel_to_whole_country:
+      avoid_all_travel_to_parts:
+      avoid_all_travel_to_whole_country: