Fix markup

Author: hoodmane

Doc/whatsnew/3.14.rst

@@ -1084,7 +1084,7 @@ The behavior of :func:`!gc.collect` changes slightly:
 Platform Support
 ================
 
-* :pep:`776: Emscripten is now an officially supported platform at
+* :pep:`776`: Emscripten is now an officially supported platform at
   :pep:`tier 3 <11#tier-3>`. As a part of this effort, more than 25 bugs in
   Emscripten libc were fixed :issue:`127146`. Emscripten now includes support
   for ``ctypes`` (:gh:`127683`), ``termios``, and ``fcntl``, as well as