Regenerate README for minesweeper to remove borders

exercism/problem-specifications#1602

Author: workingjubilee

exercises/minesweeper/README.md

@@ -1,30 +1,40 @@
 # Minesweeper
 
-Add the numbers to a minesweeper board.
+Add the mine counts to a completed Minesweeper board.
 
 Minesweeper is a popular game where the user has to find the mines using
 numeric hints that indicate how many mines are directly adjacent
 (horizontally, vertically, diagonally) to a square.
 
 In this exercise you have to create some code that counts the number of
-mines adjacent to a square and transforms boards like this (where `*`
-indicates a mine):
-
-    +-----+
-    | * * |
-    |  *  |
-    |  *  |
-    |     |
-    +-----+
-
-into this:
-
-    +-----+
-    |1*3*1|
-    |13*31|
-    | 2*2 |
-    | 111 |
-    +-----+
+mines adjacent to a given empty square and replaces that square with the
+count.
+
+The board is a rectangle composed of blank space (' ') characters. A mine 
+is represented by an asterisk ('\*') character.
+
+If a given space has no adjacent mines at all, leave that square blank.
+
+## Examples
+
+For example you may receive a 5 x 4 board like this (empty spaces are
+represented here with the '·' character for display on screen):
+
+```
+·*·*·
+··*··
+··*··
+·····
+```
+
+And your code will transform it into this:
+
+```
+1*3*1
+13*31
+·2*2·
+·111·
+```
 
 ## Rust Installation