Add DEVELOPMENT.md and SECURITY.md, add test suite

tests/conftest.py

@@ -0,0 +1,18 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+import pytest
+
+from filedust import junk
+
+
+@pytest.fixture
+def fake_home(tmp_path, monkeypatch):
+    home = tmp_path / "home"
+    home.mkdir()
+
+    monkeypatch.setattr(Path, "home", lambda: home)
+    monkeypatch.setattr(junk, "HOME", home.resolve())
+
+    return home