git mv *.hint -> README.md

There is one exception:

    $ find . -name '*.hint' -execdir git mv '{}' README.md \;
    git statufatal: destination exists, source=1992/albert/albert.hint, destination=1992/albert/README.md

Looking at the two files they differ quite a bit so I've not changed it.
I'll bring this up on GitHub.

1990/pjr/README.md

@@ -0,0 +1,65 @@
+Most Unusual Data Structure:
+
+	Peter J Ruczynski.
+	Pyramid Technology Ltd.
+	Pyramid House,
+	Solatron Road
+	Farnborough.
+	Hants GU14 7PL
+	England, U.K.
+
+
+Judges' comments:
+
+    This program prints out a string.  Can you figure out how
+    it is done?
+
+    By use of pointers to functions returning a struct of pointers 
+    to functions!
+
+    Note that some compilers will be unable to compile the
+    expression 'X=g()...' in main due to lack of temporary
+    value space.  One might want to try replacing main with:
+
+    	main(){X=s().v().o().o().l().S().d().l().i().o().w().N();}
+    
+    if this is a problem.
+
+
+Spoiler: (rot13 to read)
+
+    Guvf cebtenz cevagf bhg gur fgevat:
+
+    gur dhvpx oebja sbk whzcrq bire gur ynml qbt
+
+    ol hfr bs cbvagref gb shapgvbaf ergheavat n fgehpg bs cbvagref 
+    gb shapgvbaf!
+
+
+Selected notes from the author: (rot13 to read)
+
+    Vg vf fvzcyr gb znxr gur cebtenz cevag bgure fgevatf.  Rnpu
+    nycunorgvpny punenpgre sebz n gb m vf cevagrq bhg nf vgf
+    bccbfvgr:
+
+    	n->m o->l p->k rgp
+
+    Gb rapbqr n arj fgevat vachg gur fgevat nf vg vf zrnag gb pbzr bhg:
+
+    	K=f().i().b().b().y().F().q().y().v().b().j().A();
+
+    Abgr: F() ercerfragf n fcnpr naq A() n arjyvar.  Guvf jvyy abj
+    cebqhpr...
+
+    	uryyb jbeyq
+
+    By the way, there is actually a piece of code which is not used
+    in the original program! I leave it as an intellectual exercise
+    to the reader to find out what it is.
+
+
+Copyright (c) 1990, Landon Curt Noll & Larry Bassel.
+All Rights Reserved.  Permission for personal, educational or non-profit use is
+granted provided this this copyright and notice are included in its entirety
+and remains unaltered.  All other uses must receive prior permission in writing
+from both Landon Curt Noll and Larry Bassel.