Load the child themes translated strings.
If the current locale exists as a .mo file in the child themes root directory, it will be included in the translated strings by the $domain.
The .mo files must be named based on the locale exactly.
(string) (Required) Text domain. Unique identifier for retrieving translated strings.
(string) (Optional) Path to the directory containing the .mo file.
Default value: false
(bool) True when the theme textdomain is successfully loaded, false otherwise.