Merge branch 'document-osm-country-grid' of https://github.com/mtmail/Nominatim

diff --combined docs/mkdocs.yml
index 3f9ab8a9e8052f73655b192392b1754f0f746bc3,271fd207e09e0346fd5d7b34bb5c3035c74dab6f..69926f4efc1fcf4ac09bc0aea92dbd2229df61b1
--- 1/docs/mkdocs.yml
--- 2/docs/mkdocs.yml
+++ b/docs/mkdocs.yml
@@@ -20,10 -20,10 +20,11 @@@ pages
          - 'Troubleshooting' : 'admin/Faq.md'
      - 'Developers Guide':
          - 'Overview' : 'develop/overview.md'
 +        - 'Place Ranking' : 'develop/Ranking.md'
      - 'External Data Sources':
          - 'Overview' : 'data-sources/overview.md'
          - 'US Census (Tiger)': 'data-sources/US-Tiger.md'
+         - 'Country Grid': 'data-sources/Country-Grid.md'
      - 'Appendix':
          - 'Installation on CentOS 7' : 'appendix/Install-on-Centos-7.md'
          - 'Installation on Ubuntu 16' : 'appendix/Install-on-Ubuntu-16.md'