v3.0.0-alpha4

What's Changed

• Add some clarity around available versions and level of support by @meatballhat in #1744
• Feat: Add value source by @dearchap in #1745
• Fix:(issue_1644) Run persistent flag action by @dearchap in #1742
• Document slice flags as part of examples (v3) by @carhartl in #1750
• Consolidate all App code into Command by @meatballhat in #1746
• Output usage errors to ErrWriter by @kke in #1758
• Some docs housekeeping and minor cleanups by @meatballhat in #1752
• Reworking value source API by @meatballhat in #1760
• Collapse int64 and int flag types by @meatballhat in #1765

New Contributors

• @kke made their first contribution in #1758

Full Changelog: v3.0.0-alpha3...v3.0.0-alpha4