Fix compilation and README of 2006/borsanyi

The Makefile needs -lpthread because not all systems implicitly link it
in. I tentatively noted this fix in the README.md but I'm not sure about
it as it's nothing special at all.

Format fix README.md. I note that I could not add <>s to the email
address as for some reason (in particular the dot in the email early on)
caused rdiscount (or I think - vim syntax certainly had a problem).

2006/borsanyi/Makefile

@@ -73,7 +73,7 @@ CFLAGS= ${CSTD} ${CWARN} ${ARCH} ${CDEFINE} ${CINCLUDE} ${OPT}
 
 # Libraries needed to build
 #
-LIBS=
+LIBS= -lpthread
 
 # C compiler to use
 #

2006/borsanyi/README.md

@@ -1,12 +1,8 @@
 # Most Useful
 
-    Szabolcs Borsanyi
-    Department of Physics and Astronomy
-    University of Sussex
-    Brighton
-    East Sussex BN1 9QH
-    United Kingdom
-    s.borsanyi at sussex dot ac dot uk
+Szabolcs Borsanyi  
+United Kingdom  
+s.borsanyi at sussex dot ac dot uk  
 
 ## To build:
 
@@ -14,6 +10,10 @@
 make
 ```
 
+[Cody Boone Ferguson](/winners.html#Cody_Boone_Ferguson) fixed (the Makefile)
+under some systems where the `lpthread` was not implicitly linked in. Thank you
+Cody!
+
 ## To run:
 
 ```sh
@@ -46,24 +46,27 @@ anti-CAPTCHA tools.
 Most spam robots collect email addresses from the web sites of
 innocent people, like you. Conference organizers cannot disclose
 the participant's address to prevent malicious users from
-grabbing them. One solution is to write as my_email _at_ address
-_dot_ com. But robots are clever enough to sort that out.  A
+grabbing them. One solution is to write as `my_email _at_ address
+_dot_ com`. But robots are clever enough to sort that out.  A
 more sophisticated approach is to create an image file with the
 email address and put that on the web page.
 
-This program creates a GIF image file from the address given
-in the command line. To avoid complications with patent issues
-the LZW compression feature is not used. A typical email address
-is stored in less than 1-2 kilobytes.
+This program creates a GIF image file from the address given in the command
+line. To avoid complications with patent issues the [LZW
+compression](https://en.wikipedia.org/wiki/Lempel-Ziv-Welch) feature is not
+used. A typical email address is stored in less than 1-2 kilobytes.
 
 ### Usage:
 
-        $ gcc email.c -lpthread -o email
-        $ ./email my@email.address.com > email.gif
-        $ my_favourite_gif_viewer email.gif
+```sh
+make all
+./borsanyi my@example.com > email.gif
+my_favourite_gif_viewer email.gif
+```
 
 The address cannot be longer than 42 characters, and may consist of
-the characters: a-z_A-Z0-9@.-
+the characters: `a-z_A-Z0-9@.-`.
+
 The program is (like email addresses are) case insensitive.
 
 ### Obfuscation:
@@ -73,26 +76,27 @@ entry supports up to 25 cores.  The odd names in the bottom
 part of the program do have a meaning, they are not there just
 for obfuscation. The preprocessor is used to keep the program
 small, in fact, everything is a macro. Are you familiar with
-the GIF format? Studying this program will give you a (very
-little) insight.
+the GIF format? Studying this program will give you a (very)
+little insight.
 
 ### Questions:
 
 After analyzing the source code, try to answer these questions:
+
 1. How can you add a further supported symbol?
 2. Can you alter the look of the output characters?
 3. What limits the number of input characters to 42?
 
 ### Portability:
 
-The program uses posix threads (using the linker flag -lpthread).
+The program uses posix threads (using the linker flag `-lpthread`).
 The program accepts email addresses not longer than 42 bytes
-composed from letters, digits, and the @._- symbols. An address
+composed from letters, digits, and the `@._-` symbols. An address
 not obeying these rules will cause undefined behaviour.  The
 program is not expected to depend on endianness.  The standard
 output is used for a binary output, which might cause problems.
 To avoid most caveats, the program does not output the octet
-0x0a.  The program assumes the use of ASCII.
+`0x0a`.  The program assumes the use of ASCII.
 
 ## Copyright and CC BY-SA 4.0 License: