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.

2018/algmyr/README.md

@@ -3,13 +3,13 @@
     Anton Älgmyr  
     Twitter: @aalgmyr  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 cat prog.c | ./prog           # Printing garbage might break your font
@@ -17,7 +17,7 @@ cat prog.c | ./prog           # Printing garbage might break your font
 ./prog -d 2 0 out.raw         # Decode the first (0th) channel out of two
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./prog -h | ./prog -d 1 0

2018/bellard/README.md

@@ -3,19 +3,19 @@
     Fabrice Bellard  
     <https://bellard.org/>  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./prog > lena.ppm
 ```
 
-### Try:
+## Try:
 
 ```sh
 eog lena.ppm # On Linux

2018/burton1/README.md

@@ -3,19 +3,19 @@
     Dave Burton  
     <http://ioccc.snox.net>  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./prog < any-file
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./prog < prog

2018/burton2/README.md

@@ -3,19 +3,19 @@
     Dave Burton  
     <http://ioccc.snox.net>  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./prog [-tcksri] < file.c
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./prog -i < prog.c

2018/ciura/README.md

@@ -3,19 +3,19 @@
     Marcin Ciura <mciura@gmail.com>  
     Twitter: @mciura  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./prog < text
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./prog < Makefile

2018/endoh1/README.md

@@ -3,19 +3,19 @@
     Yusuke Endoh  
     Twitter: @mametter  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./prog < textfile > output.gif
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./prog < golem.txt > golem.gif

2018/endoh2/README.md

@@ -3,19 +3,19 @@
     Yusuke Endoh  
     Twitter: @mametter  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./prog
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./prog | tee prog_next.c

2018/ferguson/README.md

@@ -5,19 +5,19 @@ Cody Boone Ferguson <weasel@xexyl.net>
 [https://xexyl.net](https://xexyl.net)  
 Mastodon: [@xexyl@fosstodon.org](https://fosstodon.org/@xexyl)      
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./weasel
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./weasel words

2018/giles/README.md

@@ -65,13 +65,13 @@ or set the following environment variable:
 export SDL2_INCLUDE_ROOT=/usr
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./prog
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./prog ioccc.txt

2018/hou/README.md

@@ -2,13 +2,13 @@
 
     Qiming HOU  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./prog < input.json > output.html
@@ -16,7 +16,7 @@ make
 
 View `output.html` in a browser.
 
-### Try:
+## Try:
 
 ```sh
 grep -e '[-?+*/^&|.<>=]' prog.c

2018/mills/README.md

@@ -3,19 +3,19 @@
     Christopher Mills <mrxo@sonic.net>  
     Twitter: @MisterXopher  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./prog
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./prog

2018/vokes/README.md

@@ -3,19 +3,19 @@
     Scott Vokes  
     Twitter: @silentbicycle  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 ./prog < example-1.txt
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./prog < example-2.txt

2018/yang/README.md

@@ -3,13 +3,13 @@
     Don Yang  
     <http://uguu.org/>  
 
-# To build:
+## To build:
 
 ```sh
 make
 ```
 
-### To run:
+## To run:
 
 ```sh
 more generated1.c
@@ -17,7 +17,7 @@ more generated2.c
 more generated3.c
 ```
 
-### Try:
+## Try:
 
 ```sh
 ./left < prog.c