Wagtail-icon-chooser

Fixes

- Return None instead of throwing error when no icon name supplied

What's Changed

- Check that icon Id exists for every svg def before adding to chooser container

**Full Changelog**: https://github.com/wmo-raf/wagtail-icon-chooser/compare/0.0.5...0.0.6

Features
- Add function to get svg sprites for a given list of icons

Bug Fixes
- Fix setting correct icon id for svg saved as symbol

- Catch any icon parsing error

- Update to load svg defined as symbol

- Add `svg_icon` template tag for getting individual svgs