Fixed #25928 -- Clarified precendence of USE_THOUSAND_SEPARATOR and locale formats.

A boolean that specifies whether to display numbers using a thousand separator.

When :setting:`USE_L10N` is set to ``True`` and if this is also set to

``True``, Django will use the values of :setting:`THOUSAND_SEPARATOR` and

:setting:`NUMBER_GROUPING` to format numbers.

:setting:`NUMBER_GROUPING` to format numbers unless the locale already has an

existing thousands separator. If there is a thousands separator in the locale

format, it will have higher precedence and will be applied instead.

See also :setting:`DECIMAL_SEPARATOR`, :setting:`NUMBER_GROUPING` and

:setting:`THOUSAND_SEPARATOR`.