add missing 'direct path' to provider 'type' attribute definition (#23813)

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## Description
Add the 3rd option allowing to pass a direct path to configure
`provider.type` attribute

## Related issues or tickets
N/A

## Reviews

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- [ ] Technical review
- [x] Editorial review
- [ ] Product review

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Signed-off-by: Guillaume Lours <[email protected]>
Co-authored-by: Nicolas De loof <[email protected]>
Co-authored-by: Allie Sadler <[email protected]>

Author: 3 people

content/manuals/compose/how-tos/provider-services.md

@@ -81,6 +81,7 @@ The `type` field in a provider service references the name of either:
 
 1. A Docker CLI plugin (e.g., `docker-model`)
 2. A binary available in the user's PATH
+3. A path to the binary or script to execute
 
 When Compose encounters a provider service, it looks for a plugin or binary with the specified name to handle the provisioning of the requested capability.