Add missing files to _summary.md

docs/_summary.md

@@ -15,6 +15,7 @@
   * [Space Cadet](space_cadet_shift.md)
   * [Tap Dance](tap_dance.md)
   * [Mouse keys](mouse_keys.md)
+  * [Unicode](unicode.md)
 
 * Reference
   * [Glossary](glossary.md)
@@ -22,21 +23,23 @@
   * [Keycodes](keycodes.md)
     * [Basic Keycodes](basic_keycodes.md)
     * [Quantum Keycodes](quantum_keycodes.md)
-  * [The Config File](config_options.md)
+  * [The `config.h` File](config_options.md)
   * [Customizing Functionality](custom_quantum_functions.md)
   * [Documentation Best Practices](documentation_best_practices.md)
+  * [Unit Testing](unit_testing.md)
   
-* For makers and modders
+* For Makers and Modders
   * [Adding a keyboard to QMK](adding_a_keyboard_to_qmk.md)
-  * [Porting your keyboard to QMK](porting_your_keyboard_to_qmk.md)
-  * [Modding your keyboard](modding_your_keyboard.md)
   * [Adding features to QMK](adding_features_to_qmk.md)
+  * [Hand Wiring Guide](hand_wiring.md)
   * [ISP flashing guide](isp_flashing_guide.md)
+  * [Modding your keyboard](modding_your_keyboard.md)
+  * [Porting your keyboard to QMK](porting_your_keyboard_to_qmk.md)
 
-* For Deeper Understanding
+* For a Deeper Understanding
   * [How Keyboards Work](basic_how_keyboards_work.md)
   * [Understanding QMK](understanding_qmk.md)
   
-* Other topics
+* Other Topics
   * [General FAQ](faq.md)
   * [Using Eclipse with QMK](eclipse.md)