Refactor terminology and update UI for archiving feature

- Changed button text and messages from "crawl" to "archive" for clarity.
- Updated HTML elements to reflect the new terminology and improve user guidance.
- Modified footer content to emphasize local-first archiving and provide source link.
- Added a link to the project's repository in the index page and test to ensure it appears.

tests/test_main.py

@@ -35,6 +35,7 @@ def test_capture_routes_are_scoped_to_the_browser_session(tmp_path, monkeypatch)
         assert homepage.status_code == 200
         assert "Archive the web." in homepage.text
         assert "Website Downloader & Offline Archive Tool" in homepage.text
+        assert "https://git.zerofucks.io/kstyagi/website-downloader" in homepage.text
         assert client.get("/api/captures").status_code == 401
 
         created = client.post(