Improvements

* Update help text to prefix tool commands with 'fastlane' (#8214)
* Add optional date_format parameter to `changelog_from_git_commits` action (#8030)
* support create/update upload mechanism in `hockey` action (#8110)
* Better handling fo supported platforms (#8124)
* Properly catch all kinds of errors, including parsing errors, while loading plugins #8154 (#8166)
* Catch and print exceptions occuring in error block
* html encode all error messages (#8104)
* [deliver] respect file extension based on users uploaded one. (#7868)
* [frameit] layout improvements (#8031)
* [frameit] Provide option to stack keyword on top of title (#8098)
* [gym] Provide detailed error message on failure #6292
* [pilot] Remove the hardcoded value for external distribution (#8191)
* [scan] Fix retrieval of simulator logs (#8125)
* [scan] support toolchain parameter (#8172)
* [sigh] Fix option conflicts (#8129)
* [sigh] Fix tvos profile name (#8123)
* [spaceship] Add Webpush Id support  (#6943)
* [spaceship] Show error message if device_details can't be detected (#8205)

https://github.com/fastlane/fastlane/releases/tag/2.15.0
