Our RST is good enough for the strictest parsing \o/

switch to --strict == --halt 1

ref: https://docutils.sourceforge.io/docs/user/config.html#report-level

doc/Makefile.am

 #
 #
-RST2ANY_FLAGS = --halt=2
+RST2ANY_FLAGS = --strict
 
 EXTRA_DIST = changes.rst changes.html