Support local actions defined in repository

**Is your feature request related to a problem? Please describe.**
I have a few locally created actions in the `.github/actions` directory but validation and autocomplete don't seem to work on these actions.

I have the following yaml file at `.github/actions/wait-for-deployment-action`

```yaml
name: Wait for deployment
description: |
Block until a deployment is finished for the pushed commit,
and get the URL for running any further tests.
branding:
icon: clock
color: black

inputs:
github-token:
description: Your GitHub access token
required: true
environment:
description: The deployment environment to wait for
timeout:
description: The number of seconds after which to fail if no deployment is found.
default: 30
interval:
description: The number of seconds to wait between repeated checks for deployments.
default: 5
sha:
description: |
The commit SHA to wait for. Defaults to the current commit SHA. For PRs, this is the merge commit SHA.
So provide ${{ github.event.pull_request.head.sha }} instead.

outputs:
url:
description: The deployment URL
id:
description: The GitHub deployment id

runs:
using: node16
main: dist/index.js
```

The below shows an attempt to autocomplete the params expected by a local action:

**Describe the solution you'd like**
For local actions to be validated and provide autocomplete for locally defined actions.

Commencez par localiser les points d’entrée de l’extension pour la validation des workflows et l’autocomplétion des paramètres d’action, puis comparez leur traitement des métadonnées de l’action locale dans `.github/actions/wait-for-deployment-action`. Utilisez le YAML d’action présenté, y compris ses inputs et outputs, comme cas de validation et de complétion ; le travail est terminé lorsque les actions locales fournissent les deux sans perdre le comportement existant.

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