[Uk][Guide] intro-yii.md [skip ci]
Allow single items to set their encoding option
Allow an item to choose if it's encoded.
add concept-components.md
Update concept-components.md
Update CHANGELOG.md
Update CHANGELOG.md
Fixes #4114: Added Security::generateRandomHexKey(), used it for various tokens and default key generation
guide WIP [skip ci]
translated docs (structure-widgets.md) to russian
Fixed changelog
Fixes #4127: `CaptchaValidator` clientside error message wasn't formed properly
Adjusted exception message when pdkdbf2 is set but environment isn't OK
[Uk][Guide] intro-upgrade-from-v1.md [skip ci]
Remove double "the"
'autoGenerateSecretKey' mention removed from upgrade note about `Security`