fix(docs): redirect /gh-aw (no trailing slash) to /gh-aw/

[Copilot]

GET /gh-aw returned 404 instead of redirecting to /gh-aw/, and the resulting 404 page rendered a doubled canonical URL (https://github.github.com/gh-aw/gh-aw/).

Change

Added trailingSlash: 'always' to docs/astro.config.mjs:

export default defineConfig({
    site: 'https://github.github.com',
    base: '/gh-aw/',
    trailingSlash: 'always',

This instructs Astro to redirect any no-trailing-slash path to its canonical trailing-slash form — covering both the dev server and static build output. Fixes the base path 404 and the bad canonical URL as a consequence (the 404 page is no longer served for /gh-aw). No other pages are affected since all existing links already use trailing slashes.

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[Copilot]

Pull request overview

Updates the Astro docs site configuration to ensure requests to the base path without a trailing slash (e.g., /gh-aw) resolve to the canonical trailing-slash URL (/gh-aw/), avoiding a 404 and incorrect canonical URL rendering.

Changes:

• Set trailingSlash: 'always' in the Astro config to enforce trailing-slash canonical URLs (and redirect slashless paths).

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

This config change introduces an important routing/redirect behavior but there’s no regression test covering it. Since this repo already runs Playwright against the dev server (see docs/playwright.config.ts), please add a Playwright test that navigates to /gh-aw (no trailing slash) and asserts it redirects/lands on /gh-aw/ (and ideally that it’s not the 404 page / canonical URL is correct). This will prevent the base-path 404 + doubled-canonical regression from reappearing.