Use PHP short array syntax, converted with https://github.com/thomasbachem/php-short-array-syntax-converter .
Fixed unused use statements with php-cs-fixer.
Initial commit of 'Data is empty' condition with unit test.
Merge pull request #69 from paranojik/8.x-3.x-dataIsEmpty

#2281081 - Port "Data value is empty (data_is_empty)" condition to 8.x
Move documentation to separate repository.
Merge pull request #70 from fubhy/move-docs

Move documentation to separate repository.
Implementation of the List count comparison condition.
Merge pull request #73 from paranojik/8.x-3.x-listCountIs

Implementation of the List count comparison condition.
Implemented data selector application in rules state.
Removed debug statement.
Added integration test for the data selector on nodes.
Improved data selector to forward direct list access to the first entry.
Apply proper sanitization to rules evaluation exception messages.