Update preprocessing.md

Author: 5P5

docs/preprocessing.md

@@ -291,7 +291,7 @@ Apart from those, the Pug preprocessor accepts:
 
 **Template blocks:**
 
-Some of Svelte's template syntax is invalid in Pug. `svelte-preprocess` provides some pug mixins to represent svelte's `{#...}{/...}` blocks: `+if()`, `+else()`, `+elseif()`, `+each()`, `+key()`, `+await()`, `+then()`, `+catch()`, `+html()`, `+const()`, `+debug()`.
+Some of Svelte's template syntax is invalid in Pug. `svelte-preprocess` provides some pug mixins to represent svelte's `{#...}{/...}` and `{@...}` blocks: `+if()`, `+else()`, `+elseif()`, `+each()`, `+key()`, `+await()`, `+then()`, `+catch()`, `+html()`, `+const()`, `+debug()`, `+snippet()`, `+render()`.
 
 ```pug
 ul