Fix markdown formatting for examples.

examples/fluid.md

@@ -4,29 +4,24 @@
 >>> from polyomino.board import Chessboard
 >>> from polyomino.constant import MONOMINO, DOMINO
 >>> from polyomino.tileset import many
-
 ```
 
 ```python
 >>> Chessboard()
 <polyomino.board.Chessboard object at ...>
-
 ```
 
 ```python
 >>> Chessboard().tile_with_many(DOMINO)
 <polyomino.problem.TilingProblem object at ...>
-
 ```
 
 ```python
 >>> Chessboard().tile_with_set(many(DOMINO).and_repeated_exactly(2, MONOMINO))
 <polyomino.problem.TilingProblem object at ...>
-
 ```
 
 ```python
 >>> Chessboard().tile_with_set(many(DOMINO).and_repeated_exactly(2, MONOMINO)).with_heuristics()
 <polyomino.problem.TilingProblem object at ...>
-
 ```

examples/gardner.md

@@ -7,7 +7,6 @@ These examples are taken from chapter 13 of 'Mathematical Puzzles and Diversions
 >>> from polyomino.constant import ONESIDED_TETROMINOS
 >>> from polyomino.constant import TETROMINOS, ALL_PENTOMINOS
 >>> from polyomino.tileset import many, repeated_exactly, any_number_of
-
 ```
 >[...]  
 >In Chapter 3 (problem 3) we considered a polyomino problem dealing with the placing of dominoes on a mutilated chessboard.
@@ -17,20 +16,17 @@ These examples are taken from chapter 13 of 'Mathematical Puzzles and Diversions
 ```python
 >>> Chessboard().remove((0, 0)).remove((7, 7)).tile_with_many(DOMINO)
 <polyomino.problem.TilingProblem object at ...>
-
 ```
 
 [An impossible tiling will give the solution `None`.]
 
 ```python
 >>> Rectangle(4, 4).remove((0, 0)).remove((3, 3)).tile_with_many(DOMINO).solve()
-
 ```
 
 ```python
 >>> Chessboard().remove((0, 0)).remove((0, 7)).tile_with_many(DOMINO).solve().tiling
 [[(0, 1), (0, 2)], [(0, 3), (0, 4)], [(0, 5), (0, 6)], [(1, 0), (1, 1)], [(1, 2), (1, 3)], [(1, 4), (1, 5)], [(1, 6), (1, 7)], [(2, 0), (2, 1)], [(2, 2), (2, 3)], [(2, 4), (2, 5)], [(2, 6), (2, 7)], [(3, 0), (3, 1)], [(3, 2), (3, 3)], [(3, 4), (3, 5)], [(3, 6), (3, 7)], [(4, 0), (4, 1)], [(4, 2), (4, 3)], [(4, 4), (4, 5)], [(4, 6), (4, 7)], [(5, 0), (5, 1)], [(5, 2), (5, 3)], [(5, 4), (5, 5)], [(5, 6), (5, 7)], [(6, 0), (6, 1)], [(7, 0), (7, 1)], [(6, 2), (6, 3)], [(7, 2), (7, 3)], [(6, 4), (6, 5)], [(7, 4), (7, 5)], [(6, 6), (6, 7)], [(7, 6), (7, 7)]]
-
 ```
 
 ```python
@@ -124,7 +120,6 @@ These examples are taken from chapter 13 of 'Mathematical Puzzles and Diversions
 ```python
 >>> [name for name in ONESIDED_TETROMINOS if Chessboard().tile_with_many(ONESIDED_TETROMINOS[name]).solve() is None]
 ['S', 'Z']
-
 ```
 
 As mentioned on p118, there is an easy argument to show that this is impossible - naive search is computationally intractable.
@@ -153,5 +148,4 @@ As mentioned on p118, there is an easy argument to show that this is impossible
 +   +-+ +-+ +-+ +
 |   |     | |   |
 +-+-+-+-+-+-+-+-+
-
 ```

examples/more.md

@@ -1,7 +1,6 @@
 ```python
 >>> from polyomino.board import Irregular, Rectangle
 >>> from polyomino.constant import TETROMINOS
-
 ```
 
 ```python
@@ -42,7 +41,6 @@
 + +-+ +-+ +-+ +-+-+ +-+ +
 | |     | |     |     | |
 +-+-+-+-+-+-+-+-+-+-+-+-+
-
 ```
 
 ```python
@@ -104,5 +102,4 @@
 +-+ +-+ +
   | | | |
   +-+ +-+
-
 ```