documentation

Merge branch 'release/8.0' of https://git.zabbix.com/scm/web/documentation into feature/DEV-4799-7.5-D. Merge conflict RESOLVED in:
- zh-CN\manual\whatsnew.xliff (id=514e9582)
- ru\manual\whatsnew.xliff (id=514e9582)
- pl\manual\whatsnew.xliff (id=514e9582)
- it\manual\whatsnew.xliff (id=514e9582)
- de\manual\whatsnew.xliff (id=514e9582)
- lv\manual\whatsnew.xliff (id=514e9582)