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.

2000/bellard/README.md

@@ -0,0 +1,38 @@
+Most Specific Output:
+
+    Fabrice Bellard
+    451 chemin du mas de Matour
+    34790 Grabels
+    France
+
+    http://www.enst.fr/~bellard
+
+
+Judges' Comments:
+
+    To build:
+
+	make bellard
+
+    To run:
+
+	./bellard
+
+    This code is an nice compact example of a Modular Fast Fourier Transform.
+    While its output is very specific, the internal FFT has a wide variety
+    of uses.
+
+    Can you modify this code to produce primes such as 23523*2^70000-1,
+    48594^65536+1 or 6917!-1?
+
+
+Selected Author's Comments:
+
+    This program prints the biggest known prime number (2^6972593-1)
+    in base 10. It requires a few minutes. It uses a Modular Fast
+    Fourier Transform to compute this number in a reasonable amount
+    of time (the usual method would take ages !).
+
+    The program uses >= 64 bit 'long long' type. It should run on any
+    system with a gcc compiler.
+