UnyCloud v0.26.0

Changes in UnyCloud v0.26.0:

✅Changed README.md
✅Changed RELEASE_NOTES.md
✅Changed UNYCLOUD_VERSION
✅Changed docs/MAINTENANCE.md
✅Changed docs/installation.md
✅Changed frontend/package.json
✅Changed frontend/public/index.html
✅Changed frontend/public/manifest.json
✅Changed http/static.go

Commit: 1d1d9fb