Document Geofield features in the new documentation system

Problem/Motivation

The Geofield module is great, with an abundance of features. It looks like the documentation needs to be moved and updated from the old documentation pages to the new:

• Old: https://www.drupal.org/node/1089574
• New: https://www.drupal.org/docs/extending-drupal/contributed-modules/contrib...

Steps to reproduce

Proposed resolution

Create new pages, or move and update documentation from the old to the new documentation pages.

Remaining tasks

• ✅ Create new Geofield documentation page
• ✅ Create Geofield Proximity View (Field, Filter and Sort) page
• ✅ Document how to use GPX: Using GPX files with Geocoder and Geofield
• 🔄 Add link under "Resources" from https://www.drupal.org/project/geofield to new documentation
• 🔄 Add more pages here ...

User interface changes

API changes

Data model changes