Typo fix in 2011/fredriksson/README.md

This was found quite by accident: another pass of the file will be done
once all the README.md files have been formatted (it seems like I will
be able to resume somewhere in year 2013).

2011/fredriksson/README.md

@@ -208,7 +208,7 @@ Just say
 
 * Algorithmically, it incorporates the following
 	- (inverse) Burrows-Wheeler transform (used also e.g. in bzip2)
-	- data compression (really expansion :-), run-lenght-encoding,
+	- data compression (really expansion :-), run-length-encoding,
 	  unary coding (this is why it is expansion rather than compression)
 	- approximate string matching
 	- dynamic programming to compute the edit distance