Update src/theme/icon.rs to add Svelte icon

Author: Marcos-Gamarra

src/theme/icon.rs

@@ -562,6 +562,7 @@ impl IconTheme {
             ("sub", "\u{f02d}"),             // ""
             ("s", "\u{f471}"),               // ""
             ("svg", "\u{f1c5}"),             // ""
+            ("svelte", "\u{e697}"),          // ""
             ("swift", "\u{e755}"),           // ""
             ("swp", "\u{e62b}"),             // ""
             ("sym", "\u{e624}"),             // ""