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.

2014/MANIFEST

@@ -3,20 +3,20 @@
 2014/Makefile
 2014/birken/Makefile
 2014/birken/hint.html
-2014/birken/hint.text
+2014/birken/README.md
 2014/birken/prog.c
 2014/deak/Makefile
 2014/deak/hint.html
-2014/deak/hint.text
+2014/deak/README.md
 2014/deak/prog.c
 2014/endoh1/Makefile
 2014/endoh1/hint.html
-2014/endoh1/hint.text
+2014/endoh1/README.md
 2014/endoh1/prog.c
 2014/endoh1/src.zip
 2014/endoh2/Makefile
 2014/endoh2/hint.html
-2014/endoh2/hint.text
+2014/endoh2/README.md
 2014/endoh2/prog.c
 2014/guidelines.txt
 2014/hint.css
@@ -27,7 +27,7 @@
 2014/maffiodo1/giana.rgba
 2014/maffiodo1/giana8.wav
 2014/maffiodo1/hint.html
-2014/maffiodo1/hint.text
+2014/maffiodo1/README.md
 2014/maffiodo1/mario.level
 2014/maffiodo1/mario.rgba
 2014/maffiodo1/mario8.wav
@@ -37,32 +37,32 @@
 2014/maffiodo1/screenshot-mario.png
 2014/maffiodo2/Makefile
 2014/maffiodo2/hint.html
-2014/maffiodo2/hint.text
+2014/maffiodo2/README.md
 2014/maffiodo2/image.rgb
 2014/maffiodo2/prog.c
 2014/morgan/Makefile
 2014/morgan/hint.html
-2014/morgan/hint.text
+2014/morgan/README.md
 2014/morgan/prog.c
 2014/rules.txt
 2014/sinon/Makefile
 2014/sinon/glock.sh
 2014/sinon/hecate.sh
 2014/sinon/hint.html
-2014/sinon/hint.text
+2014/sinon/README.md
 2014/sinon/prog.c
 2014/sinon/spoiler.html
 2014/skeggs/Makefile
 2014/skeggs/hint.html
-2014/skeggs/hint.text
+2014/skeggs/README.md
 2014/skeggs/prog.c
 2014/skeggs/prog.orig.c
 2014/vik/Makefile
 2014/vik/hint.html
-2014/vik/hint.text
+2014/vik/README.md
 2014/vik/prog.c
 2014/whowon.html
 2014/wiedijk/Makefile
 2014/wiedijk/hint.html
-2014/wiedijk/hint.text
+2014/wiedijk/README.md
 2014/wiedijk/prog.c