8.15.0

What's Changed

• Prepare main branch for next release cycle by @pzl in #495
• cherry-pick update custom documentation (#497) by @intxgo in #498
• remove unreleased document fields documentation which were accidental… by @intxgo in #501
• Fix formatting/order from ecs build tool by @pzl in #505
• [8.15] add truncated_stack to api.behaviors documentation by @jdu2600 in #504
• Add event.dataset to api datastream by @pzl in #507
• add heartbeat billable field by @joeypoon in #510
• 8.15 update custom documentation by @intxgo in #513
• Add file.origin_referrer_url and file.origin_url to FileEvent by @AsuNa-jp in #514
• Prepare 8.15 release by @pzl in #515

Full Changelog: v8.14.0...v8.15.0