Allow any ASCII whitespace instead of just space after `<%`

sailfish-compiler/src/parser.rs

@@ -165,7 +165,7 @@ impl<'a> ParseStream<'a> {
                 token_kind = TokenKind::BufferedCode { escape: None };
                 start += 1;
             }
-            Some(b' ') => {}
+            Some(b) if b.is_ascii_whitespace() => {}
             Some(b'%') if self.source[start..] == self.block_delimiter.1 => {}
             _ => return Err(self.error("Invalid block syntax")),
         }