Refactor comments and CSS for improved clarity in Khoj plugin

- Translated comments from French to English for better accessibility and understanding.
- Updated CSS comment for loading animation to reflect the change in language.
- Enhanced code readability by ensuring consistent language usage across multiple files.
- Improved user experience by clarifying the purpose of various functions and settings in the codebase.

src/interface/obsidian/styles.css

@@ -813,7 +813,7 @@ img.copy-icon {
     display: block;
 }
 
-/* Animation de chargement */
+/* Loading animation */
 .khoj-loading {
     display: flex;
     justify-content: center;