[Docs] Clarify layer transparency keymap.md (#9081)

* Revised the grammar and clarity of the Layer Precedence and Transparency

* Update docs/keymap.md

* Update docs/keymap.md

* Update docs/keymap.md

* Update docs/keymap.md

* Update docs/keymap.md

* Update docs/keymap.md

* Update docs/keymap.md

docs/keymap.md

@@ -71,10 +71,22 @@ On the other hand, you can change `layer_state` to overlay the base layer with o
 
 
 ### Layer Precedence and Transparency
-Note that ***higher layer has higher priority on stack of layers***, namely firmware falls down from top layer to bottom to look up keycode. Once it spots keycode other than **`KC_TRNS`**(transparent) on a layer it stops searching and lower layers aren't referred.
+Note that ***higher layers have higher priority within the stack of layers***. The firmware works its way down from the highest active layers to look up keycodes. Once the firmware locates a keycode other than `KC_TRNS` (transparent) on an active layer, it stops searching, and lower layers aren't referenced.
 
-You can place `KC_TRANS` on overlay layer changes just part of layout to fall back on lower or base layer.
-Key with `KC_TRANS` (`KC_TRNS` and `_______` are the alias) doesn't has its own keycode and refers to lower valid layers for keycode, instead.
+           ____________
+          /           /  <--- Higher layer
+         /  KC_TRNS  //
+        /___________//   <--- Lower layer (KC_A)
+        /___________/
+    
+    In the above scenario, the non-transparent keys on the higher layer would be usable, but whenever `KC_TRNS` (or equivalent) is defined, the keycode (`KC_A`) on the lower level would be used.
+
+**Note:** Valid ways to denote transparency on a given layer:
+* `KC_TRANSPARENT`
+* `KC_TRNS` (alias)
+* `_______` (alias)
+
+These keycodes allow the processing to fall through to lower layers in search of a non-transparent keycode to process.
 
 ## Anatomy of a `keymap.c`