doc: How to Manage WebAuthn Keys: Browser, macOS, YubiKey, etc

## Chromium

- `chrome://settings/passkeys`
- `brave://settings/passkeys`

## macOS

- Search "passkeys" in macOS Settings

## YubiKey

- YubiKey Manager GUI (**deprecated**): \
To [install the pkg on macOS without allowing admin privileges](pkgutil --expand-full ~/Downloads/foo.pkg /tmp/foo/):
```sh
pkgutil --expand-full ~/Downloads/yubikey-manager-qt-1.2.5-mac.pkg /tmp/yubikey-gui/
mv "/tmp/yubikey-gui/com.yubico.ykman.pkg/Payload/YubiKey Manager.app" /Applications/
```
- YubiCo Authenicator: \
(haven't tried it yet, but might be able to do as much or more than the CLI)
- YubiKey Manager CLI:
```sh
pkgutil --expand-full ~/Downloads/yubikey-manager-5.5.0-mac.pkg /tmp/yubikey-cli
mv /tmp/yubikey-cli/ykman.pkg/Payload/usr/local/ ~/.local/opt/yubikey-v5.5.0
ln -s yubikey-v5.5.0 ~/.local/opt/yubikey
xattr -r -d com.apple.quarantine ~/.local/opt/yubikey/
ln -s ../opt/yubikey/bin/ykman ~/.local/bin/
```
and then make sure `~/.local/bin` is in your `PATH`, such as with (or `webi` itself).
```sh
pathman add ~/.local/opt/yubikey/bin/
```

The GUI doesn't seem to do much of anything. The CLI has more options:

```sh
# this definitely shows fewer accounts that I know I have, but I didn't find them under the other options either
ykman fido credentials list --csv
```

```csv
credential_id,rp_id,user_name,user_display_name,user_id
6ccd32400f0fc8cecfbaeca6932a53612477b57629ad1d36a461ca6e01342dd93df0af0f8db9d224d0f801482f22660e,local.pocketid.app,aj@therootcompany.com,aj,302e3430313230383733343534383933363335
```

```
ykman fido credentials delete [-f]
```

Aucun fichier de documentation cible ni aucun test n’est indiqué. Commencez par localiser la section de documentation du projet, puis examinez les sections consacrées à Chromium, macOS et YubiKey, ainsi que les téléchargements qui y sont liés. La tâche est terminée lorsque les instructions de gestion des clés sont placées au bon endroit dans la documentation et que les instructions et les liens listés sont exacts.

Rédigé par le modèle d'indexation à partir du texte de l'issue.