Fix contributing.md's tree structure

Author: unsecretised

CONTRIBUTING.md

@@ -32,16 +32,22 @@ For bug fixes, and helping people to solve their github issues: see
 ├── docs # Website and documentation related stuff. If something new is added to config, then modify this as well before PR-ing
 ├── Cargo.lock 
 ├── Cargo.toml
-├── CONTRIBUTING.md
-├── EXTENSIONS.md
-├── LICENSE.md
-├── README.md
+├── CONTRIBUTING.md # Contributing guidelines and codebase structure
+├── EXTENSIONS.md   # Discussions about extensions implementation
+├── LICENSE.md      # License file
+├── README.md       # Readme file
 └── src
-    ├── app.rs        # Main app logic
-    ├── calculator.rs # Calculator logic 
-    ├── commands.rs   # Logic for different commands
-    ├── config.rs     # Configuration related stuff
-    ├── macos.rs      # Macos specific config
-    ├── main.rs       # Start app
-    └── utils.rs      # Common functions that are used across files
+    ├── app
+    │   ├── apps.rs         # Logic for the "apps" / commands that rustcast can perform
+    │   ├── tile            # Logic for the tile (rustcast window)
+    │   │   ├── elm.rs      # Logic for the elm architecture of the rustcast window (New and View)
+    │   │   └── update.rs   # Logic for the updating (elm architecture update) of the rustcast window
+    │   └── tile.rs
+    ├── calculator.rs       # Calculator logic 
+    ├── commands.rs         # Logic for different commands
+    ├── clipboard.rs        # Logic for the clipboard history feature of rustcast
+    ├── config.rs           # Configuration related stuff
+    ├── macos.rs            # Macos specific config
+    ├── main.rs             # Start app
+    └── utils.rs            # Common functions that are used across files
 ```