fixup: use indentation after template head

Co-authored-by: Jan Schultke <[email protected]>

Author: dietmarkuehl

source/exec.tex

@@ -6152,7 +6152,7 @@
 
 \begin{itemdecl}
 template<class R>
-@\exposid{state}@(coroutine_handle<promise_type> h, R&& rr);
+  @\exposid{state}@(coroutine_handle<promise_type> h, R&& rr);
 \end{itemdecl}
 
 \begin{itemdescr}