added tests, changed __main__ to cli

tests/base.py

@@ -0,0 +1,15 @@
+from tiktok_hashtag_analysis.base import TikTokDownloader, load_hashtags_from_file
+
+
+def test_scrape(tmp_path, hashtags):
+    downloader = TikTokDownloader(hashtags=hashtags[:1], data_dir=tmp_path)
+    downloader.run(download=True, plot=True, table=True, number=20)
+
+
+def test_load_hashtags_from_file(tmp_path, hashtags):
+    file = tmp_path / "hashtags.txt"
+    with open(file, "w", encoding="utf-8") as f:
+        f.write("\n".join(hashtags))
+
+    loaded_hashtags = load_hashtags_from_file(file=file)
+    assert loaded_hashtags == hashtags