Fix and add backticks for preferNone value in linting_and_formatting.md (#2770)

Co-authored-by: Jo Franchetti <jofranchetti@gmail.com>

Author: yoshida-ryuhei

runtime/fundamentals/linting_and_formatting.md

@@ -273,7 +273,7 @@ Use tabs instead of spaces for indentation
 Whether to use braces for if statements, for statements, and while statements
 
 - **Default:** `whenNotSingleLine`
-- **Possible values:** `maintain`, `whenNotSingleLine`, `always`, preferNone
+- **Possible values:** `maintain`, `whenNotSingleLine`, `always`, `preferNone`
 
 ### Configuration