GuideML 3.17

• Add basic support for @{system command with openurl command.
• Add colour theme management with new light and dark colour themes in addition to the default AmigaGuide compatible one.

What's Changed

• Make it possible to build GuideML on Haiku by @pulkomandy in #1

New Contributors

• @pulkomandy made their first contribution in #1

Full Changelog: v3.16...v3.17