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/README.md

@@ -662,7 +662,7 @@ that.
 
 [1992 Worst Abuse of the Rules]: http://www.ioccc.org/1992/nathan/nathan.hint
 [1998 ASCII / Morse code translator]: http://www.ioccc.org/1998/dorssel/dorssel.hint
-[2014 Morse audio transcoder]: http://www.ioccc.org/2014/vik/hint.text
+[2014 Morse audio transcoder]: http://www.ioccc.org/2014/vik/README.md
 [Enigma Message Procedures]: http://users.telenet.be/d.rijmenants/en/enigmaproc.htm
 [Interactive Enigma Machine]: http://enigmaco.de/enigma/enigma.html
 [enigma.1]: enigma.1