add allow_unused config to missing_docs_in_private_items (#14453)

fixes #14413
add allow_unused config to missing_docs_in_private_items for underscored
field

changelog: [`missing_docs_in_private_items`]: add allow_unused config to
missing_docs_in_private_items for underscored field

Explaination (quoted from the issue's author): When writing structures
that must adhere to a specific format (such as memory mapped I/O
structures) there are inevitably fields that are "reserved" by
specifications and thus need no documentation. In cases where private
docs are preferred but reserved fields need no explanation, having to
#[allow/expect] this lint removes the ability to check for otherwise
used fields' documentation.

0 files changed, 0 insertions, 0 deletions