Fix alphabetical order.

Author: amartini51

TSPL.docc/ReferenceManual/LexicalStructure.md

@@ -316,8 +316,8 @@ so they must be escaped with backticks in that context.
 - Keywords that begin with a number sign (`#`):
   `#available`,
   `#colorLiteral`,
-  `#elseif`,
   `#else`,
+  `#elseif`,
   `#endif`,
   `#fileLiteral`,
   `#if`,