PEP 776: Emscripten support (#4307)

Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>
Co-authored-by: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Co-authored-by: Brett Cannon <brett@python.org>

Author: 5 people

.github/CODEOWNERS

@@ -654,7 +654,7 @@ peps/pep-0772.rst  @warsaw @pradyunsg
 peps/pep-0773.rst  @zooba
 peps/pep-0774.rst  @savannahostrowski
 peps/pep-0775.rst  @encukou
-# ...
+peps/pep-0776.rst  @hoodmane @ambv
 peps/pep-0777.rst  @warsaw
 # ...
 peps/pep-0779.rst  @Yhg1s @colesbury @mpage