Added unit test for music module

Reorganized unit tests into unit_tests directory

README.md

@@ -76,3 +76,16 @@ status ⏸ Dire Straits - Tunnel of Love [6% 14:23] 💾 24% 💻 1% 🔌 100%
 status ⏸ Dire Straits - Tunnel of Love [6% 14:23] 💾 24% 💻 1% 🔌 100% 📶 192.168.1.93 ☀️ 83°F 📅 2025 Jun 07 🕑 09:25PM -07:00
 ^C
 ```
+
+# Unit testing
+
+Use the following command to run unit tests:
+
+```shell
+$ cargo test --package unibar --bin unibar
+```
+To run a specific test, use the following:
+
+```shell
+$ cargo test --package unibar --bin unibar -- bar_modules::bar_module_weather::tests::test_get_unicode_symbol_default --exact --show-output
+```