Add comment about LC_ALL

Makefile

@@ -20,6 +20,10 @@ testD:
 testE:
 	make VERBOSE=$(VERBOSE) NODIFF=$(NODIFF) DEBUG=$(DEBUG) OPTDUMP=$(OPTDUMP) OPTS="ignoreclosebraces" -C test test
 
+# Set LC_ALL to avoid having to deal with different locales.
+# The generated .adoc files will differ in sorting and or unicode char encoding.
+# LC_ALL=C is sadly not an option here since it results in incorrect char
+# encoding in some of the files created by zsd.
 doc: export LC_ALL=en_US.UTF-8
 doc: zinit.zsh zinit-side.zsh zinit-install.zsh zinit-autoload.zsh
 	rm -rf doc/zsdoc/data doc/zsdoc/*.adoc