Improve SEO/AEO discovery surface for awesome-python.com (#3103)

* update gitignore

* feat: tighten homepage metadata

* fix: trim generated HTML whitespace

* feat(website): add discovery files and markdown alternate

* feat(website): add sitemap lastmod

* feat(seo): add Content-Signal directive to robots.txt

Signals search, ai-input, and ai-train to crawlers
via the experimental Content-Signal header in robots.txt.

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>

.gitignore

@@ -10,12 +10,12 @@ __pycache__/
 website/output/
 website/data/
 
-# claude code
-.claude/skills/
-.gstack/
-.playwright-cli/
-.superpowers/
-skills-lock.json
+# planning docs
+docs/
 
-# codex
+# agents
 .agents/
+.claude/skills/
+.superpowers/
+.playwright-cli/
+skills-lock.json