npm package.json supports binary packaging:
https://docs.npmjs.com/cli/v8/configuring-npm/package-json#bin

the npm registry documents that the binary references will be attached
to the abbreviated version object:
https://github.com/npm/registry/blob/master/docs/responses/package-metadata.md#abbreviated-version-object

unfortunately their api documentation leaves this out:
https://github.com/npm/registry/blob/master/docs/responses/package-metadata.md#abbreviated-version-objectdoc

which is likely to be the reason this was left out in gitea's initial
implementation

this response is critical for npm to install the binary in the `.bin`
folder so as to be included on the users default bin path, resulting in
immediate access to any binaries provied by the package

Signed-off-by: eleith <online-github@eleith.com>

Co-authored-by: silverwind <me@silverwind.io>