feat: initial scaffold of awesome-coding-agents tracker

Go updater that fetches AI agent coding tool repo stats via GitHub GraphQL
(batched, one query), sorts by star count, appends a daily snapshot to
data/history.jsonl, and regenerates README.md from templates/readme.tmpl.
Daily workflow at .github/workflows/update.yml refreshes rankings and
commits changes. Seed list in data/agents.yml covers 19 tracked repos.

.gitignore

@@ -0,0 +1,10 @@
+# Go build artifacts
+/awesome-coding-agents
+*.exe
+*.test
+*.out
+
+# Editor / OS noise
+.DS_Store
+.idea/
+.vscode/