Mass fixes to headers in README.md files

There were many many README.md files with the wrong heading level for
different sections. These have been changed.

To help go through the changes it should be noted I used sgit and also
here is what is changed:

The 'Try', 'To build' and 'To run' lines have two '#'s. Some had one and
others had three.

An exception is that in 1984/anonymous/README.md for the alternative
code that had three '#'s. This is not consistent yet and it might be
that only two are desired. But for now that one at least has three.

2014/maffiodo1/README.md

@@ -4,7 +4,7 @@
     <smaffer@gmail.com>  
     <http://www.assezeta.com/sandromaffiodo>  
 
-# To build:
+## To build:
 
 This entry requires SDL to be installed.
 
@@ -67,13 +67,13 @@ or set the following environment variable:
 export SDL2_INCLUDE_ROOT=/usr
 ```
 
-### To run:
+## To run:
 
 ```sh
 cat mario.level | ./prog 320 200 800 300 128 144 mario.rgba mario8.wav 10343679
 ```
 
-### Try:
+## Try:
 
 ```sh
 cat giana.level | ./prog 320 200 1000 300 192 168 giana.rgba giana8.wav 5459393