feat: scaffold starter template with TypeScript, CRD list view, CI, ArtifactHub

Adds full plugin starter template including:
- package.json with @kinvolk/headlamp-plugin devDependency and standard scripts
- tsconfig.json extending headlamp plugin config
- vitest.config.mts + vitest.setup.ts (jsdom, NODE_ENV=test, localStorage shim)
- src/index.tsx: registers sidebar entry and route for ResourceListPage
- src/components/ResourceListPage.tsx: placeholder CRD list view with TODO guide
- src/components/ResourceListPage.test.tsx: example tests using vi.mock pattern
- .github/workflows/ci.yaml: delegates to shared plugin-ci.yaml
- .github/workflows/release.yaml: delegates to shared plugin-release.yaml
- artifacthub-pkg.yml + artifacthub-repo.yml: ArtifactHub metadata with TODO markers
- renovate.json: Mend Renovate config for weekly dependency updates
- README.md: complete getting-started guide
- CONTRIBUTING.md: local dev, code style, testing, PR process
- LICENSE: Apache-2.0

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/components/ResourceListPage.test.tsx

@@ -0,0 +1,51 @@
+import { render, screen } from '@testing-library/react';
+import React from 'react';
+import { describe, expect, it } from 'vitest';
+import ResourceListPage from './ResourceListPage';
+
+vi.mock('@kinvolk/headlamp-plugin/lib/CommonComponents', () => ({
+  Loader: ({ title }: { title: string }) => <div data-testid="loader">{title}</div>,
+  SectionBox: ({ title, children }: { title: React.ReactNode; children?: React.ReactNode }) => (
+    <section>
+      {title}
+      {children}
+    </section>
+  ),
+  SectionHeader: ({ title }: { title: string }) => <h1>{title}</h1>,
+  NameValueTable: ({
+    rows,
+  }: {
+    rows: Array<{ name: React.ReactNode; value: React.ReactNode }>;
+  }) => (
+    <dl>
+      {rows.map((r, i) => (
+        <div key={i}>
+          <dt>{r.name}</dt>
+          <dd>{r.value}</dd>
+        </div>
+      ))}
+    </dl>
+  ),
+  StatusLabel: ({ status, children }: { status: string; children?: React.ReactNode }) => (
+    <span data-status={status}>{children}</span>
+  ),
+}));
+
+describe('ResourceListPage', () => {
+  it('renders the "My Plugin" heading', () => {
+    render(<ResourceListPage />);
+    expect(screen.getByText('My Plugin')).toBeInTheDocument();
+  });
+
+  it('shows the example resource group row', () => {
+    render(<ResourceListPage />);
+    expect(screen.getByText('Resource Group')).toBeInTheDocument();
+    expect(screen.getByText('your.group.io/v1')).toBeInTheDocument();
+  });
+
+  it('shows the example Kind row', () => {
+    render(<ResourceListPage />);
+    expect(screen.getByText('Kind')).toBeInTheDocument();
+    expect(screen.getByText('YourCustomResource')).toBeInTheDocument();
+  });
+});