Change references of hint.text etc. to README.md

The following files were modified:

	modified:   2012/MANIFEST
	modified:   2012/hamano/README.md
	modified:   2014/MANIFEST
	modified:   2015/MANIFEST
	modified:   2018/MANIFEST
	modified:   2018/anderson/README.md
	modified:   2018/ciura/README.md
	modified:   2018/ferguson/FILES
	modified:   2018/ferguson/weasel.1
	modified:   2018/ferguson/weasel.man
	modified:   2018/ferguson/weasel.spec
	modified:   2019/MANIFEST
	modified:   2019/karns/README.md
	modified:   2020/MANIFEST
	modified:   2020/ferguson2/README.md
	modified:   2020/ferguson2/enigma.1
	modified:   2020/ferguson2/recode.1
	modified:   years-spoiler.html
	modified:   years.html

but I am not clear on some of the changes here. For instance some of the
text changed were html anchors and I'm not sure of the implications of
it other than the fact that changing the filenames (see commits
77fb0f11a2 and
851e191519) would break the links. Whether
more needs to be done or not I do not know.

2020/ferguson2/recode.1

@@ -40,7 +40,7 @@ Source file to the recode program.
 .RS
 Markdown file with examples on how to use the recode program (along with the Enigma program).
 .RE
-\fIhint.text\fP
+\fIREADME.md\fP
 .RS
 More information on the Enigma simulator IOCCC entry.
 .RE