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.

1994/dodsond1/README.md

@@ -12,7 +12,7 @@ make all
 ```
 
 
-### Try:
+## Try:
 
 At the prompt, try entering `E3`.
 

1994/horton/README.md

@@ -14,7 +14,7 @@ make all
 `A`, `B`, `C` and `D` are numeric arguments.
 
 
-### Try:
+## Try:
 
 ```sh
 ./horton 3 2 1 0

1994/imc/README.md

@@ -14,7 +14,7 @@ make all
 where `[NUMBER]` is an optional number. Default is 5.
 
 
-### Try:
+## Try:
 
 ```sh
 ./imc 3

1994/ldb/README.md

@@ -25,7 +25,7 @@ some_command | ./ldb
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./ldb < /etc/passwd

1994/schnitzi/README.md

@@ -28,7 +28,7 @@ For more detailed information see [1994 schnitzi in bugs.md](/bugs.md#1994-schni
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./schnitzi < /etc/motd 2>/dev/null

1994/shapiro/README.md

@@ -24,7 +24,7 @@ For more detailed information see [1994 shapiro in bugs.md](/bugs.md#1994-shapir
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./shapiro

1994/smr/README.md

@@ -12,7 +12,7 @@ make all
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./smr > smr.out ; diff -s smr.out smr.c

1994/tvr/README.md

@@ -28,7 +28,7 @@ For more detailed information see [1994 tvr in bugs.md](/bugs.md#1994-tvr).
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./tvr 0 128 < tvr.color		(for color displays)

1994/weisberg/README.md

@@ -15,7 +15,7 @@ code](#alternate-code) below.
 ```
 
 
-### Try:
+## Try:
 
 ```sh
 ./weisberg | head -n 15

1994/westley/README.md

@@ -18,7 +18,7 @@ wraparound.
 There is no running as such. See below.
 
 
-### Try:
+## Try:
 
 But for something more interesting try compiling it with
 different cc arguments.  For example: