Add SEMGREP_APP_URL to environment variable list

[jkinsfather]

This environment variable is detailed in a knowledge base page and is missing from the page enumerating environment variables.

KB: https://semgrep.dev/docs/kb/semgrep-appsec-platform/semgrep-login-cli-tenant

Thanks for improving Semgrep Docs 😀

Please ensure

• A subject matter expert (SME) reviews the content
• A technical writer reviews the content or PR
• This change has no security implications or else you have pinged the security team
• Redirects are added if the PR changes page URLs
• If you have changed any header tag links (doc/#this-kind-of-anchor), update all instances of that link

---

Adding a new documentation page? Click to expand the checklist

• Create .md or .mdx file in /docs/[section]/ with frontmatter: slug, title, description, displayed_sidebar, tags
• Add page to appropriate sidebar in /sidebars.js (shows in side nav)
• If adding the doc in a new directory: Update /src/theme/Navbar/Content/index.tsx → add path to getCurrentSection() (highlights top nav)

Sidebars fields for displayed_sidebar:
scanSidebar | rulewritingSidebar | devSidebar | learnSidebar | aboutSidebar | kbSidebar | whatsSemgrepSidebar

Top nav fields for getCurrentSection():
'scan' | 'write-rules' | 'learning-guides' | 'help' | 'explore'

[netlify]

✅ Deploy Preview for semgrep-docs-prod ready!

Name	Link
🔨 Latest commit	8b7caf7
🔍 Latest deploy log	https://app.netlify.com/projects/semgrep-docs-prod/deploys/698e268b6069c0000736f45b
😎 Deploy Preview	https://deploy-preview-2494--semgrep-docs-prod.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.