Fix heading level of 'Try' section

It was agreed to be '## Try:' but there were many files where it was
'### Try:'. This has been corrected.

2014/birken/README.md

@@ -18,7 +18,7 @@ there is a firewall issue, and also lets you redefine the timing constant,
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./prog < README.md

2014/deak/README.md

@@ -17,7 +17,7 @@ code](#alternate-code) below.
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./prog

2014/endoh1/README.md

@@ -12,7 +12,7 @@ make
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./try.sh

2014/endoh2/README.md

@@ -12,7 +12,7 @@ make
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 echo Hello | ./prog

2014/maffiodo1/README.md

@@ -40,7 +40,7 @@ The parameters to the program are:
 note on macOS.
 
 
-### Try:
+## Try:
 
 ```sh
 ./giana.sh

2014/maffiodo2/README.md

@@ -26,7 +26,7 @@ For more detailed information see [2014 maffiodo2 in bugs.md](/bugs.md#2014-maff
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./try.sh

2014/morgan/README.md

@@ -12,7 +12,7 @@ make
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./try.sh

2014/sinon/README.md

@@ -12,7 +12,7 @@ cp -f prog.c run.c; ./hecate.sh
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./try.sh

2014/vik/README.md

@@ -27,7 +27,7 @@ For more detailed information see [2014 vik in bugs.md](/bugs.md#2014-vik).
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 echo 'Want to hear me beep?' | ./prog > audio_file.raw

2014/wiedijk/README.md

@@ -12,7 +12,7 @@ make
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./try.sh