[feat] Add contributing guidelines for the registry

Author: sfc-gh-bnisco

.vscode/settings.json

@@ -0,0 +1,8 @@
+{
+  "json.schemas": [
+    {
+      "fileMatch": ["components/registry/components/*.json"],
+      "url": "./components/registry/schemas/component.schema.json"
+    }
+  ]
+}

components/registry/README.md

@@ -0,0 +1,118 @@
+# Component Registry
+
+This repo includes a **community-maintained component registry** of Streamlit components under [`components/registry/components/`](components/). Each file is a small JSON document describing a single component found on the internet.
+
+If you maintain a Streamlit Component, we’d love for you to add it here via a pull request!
+
+## Quick submit (GitHub web editor)
+
+1. **Fork** this repository.
+2. In your fork, open [`components/registry/components/`](components/) and click **Add file → Create new file**.
+3. Name your file: `components/registry/components/<slug>.json`
+   - Use a short, URL-safe slug like `streamlit-my-component.json` (lowercase + hyphens is best).
+4. Copy/paste the **Starter template** below, fill in your values.
+5. Commit to a new branch in your fork.
+6. Open a **Pull Request** back to this repo.
+
+When you open the PR, CI will automatically validate your JSON.
+
+## Starter template (minimal valid)
+
+> Tip: If you’re editing in VS Code / GitHub’s web editor, you should get live validation + autocomplete from the schema once `.vscode/settings.json` is present in the repo.
+
+```json
+{
+  "schemaVersion": 1,
+  "title": "My Component",
+  "author": {
+    "github": "your-github-username",
+    "displayName": "Your Name (optional)"
+  },
+  "links": {
+    "github": "https://github.com/OWNER/REPO",
+    "pypi": null,
+    "demo": null,
+    "docs": null
+  },
+  "media": {
+    "image": null
+  },
+  "install": {
+    "pip": "pip install your-package-name"
+  },
+  "governance": {
+    "enabled": true,
+    "notes": null
+  },
+  "categories": ["Widgets"]
+}
+```
+
+## Requirements (what CI checks)
+
+CI runs [`components/registry/scripts/validate.py`](scripts/validate.py) on every PR that touches `components/registry/components/**`.
+
+### Schema requirements
+
+Your JSON must conform to [`components/registry/schemas/component.schema.json`](schemas/component.schema.json). Key points:
+
+- **`schemaVersion`**: must be `1`.
+- **`title`**: 1–80 characters.
+- **`author.github`**: GitHub username _without_ `@`.
+- **`links.github`**: must be a repo URL like `https://github.com/<owner>/<repo>` (no extra path segments).
+- **`links.pypi`**: PyPI project name (not a URL), or `null`.
+- **No extra keys**: the schema uses `additionalProperties: false`, so don’t add custom fields.
+
+### Policy checks beyond schema (common CI failures)
+
+The validator enforces a few “lint” rules to keep the registry stable:
+
+- **Unique repo**: `links.github` must be unique across all submissions. If the same repo was already submitted, CI will fail.
+- **HTTPS only**: all URLs must be `https://` and must not use `javascript:`, `data:`, or `file:` schemes.
+- **Stable images** (`media.image`): must be a stable `https://` URL.
+  - Signed/expiring URLs (S3/GCS/CloudFront-style query params like `X-Amz-Signature`, `Expires`, etc.) are rejected.
+  - Proxy hosts like `camo.githubusercontent.com` are rejected.
+- **File size**: each `components/registry/components/*.json` must be ≤ 50 KB.
+
+## Categories
+
+Pick **at least one** category (you can pick multiple). Allowed values are:
+
+- `LLMs`
+- `Widgets`
+- `Charts`
+- `Authentication`
+- `Connections`
+- `Images & video`
+- `Audio`
+- `Text`
+- `Maps`
+- `Dataframes`
+- `Graphs`
+- `Molecules & genes`
+- `Code editors`
+- `Page navigation`
+- `Developer tools`
+- `Integrations`
+
+## Self-check your submission (optional, but recommended)
+
+### Option A: No local setup
+
+Open a **draft PR** and let CI validate it automatically.
+
+### Option B: Run the validator locally
+
+From the repo root:
+
+```bash
+uv venv .venv
+uv pip install -r requirements.txt
+.venv/bin/python ./components/registry/scripts/validate.py
+```
+
+If it prints `OK: all validated files passed.`, your submission is valid.
+
+## What not to edit
+
+- Don’t edit `components/registry/compiled/components.json` directly — it’s a generated artifact.