description.md: rm trailing spaces

exercises/kindergarten-garden/description.md

@@ -7,8 +7,8 @@ actual dirt, and grow actual plants.
 
 They've chosen to grow grass, clover, radishes, and violets.
 
-To this end, the children have put little cups along the window sills, and 
-planted one type of plant in each cup, choosing randomly from the available 
+To this end, the children have put little cups along the window sills, and
+planted one type of plant in each cup, choosing randomly from the available
 types of seeds.
 
 ```text
@@ -23,7 +23,7 @@ There are 12 children in the class:
 - Eve, Fred, Ginny, Harriet,
 - Ileana, Joseph, Kincaid, and Larry.
 
-Each child gets 4 cups, two on each row. Their teacher assigns cups to 
+Each child gets 4 cups, two on each row. Their teacher assigns cups to
 the children alphabetically by their names.
 
 The following diagram represents Alice's plants:

exercises/nucleotide-count/description.md

@@ -1,7 +1,7 @@
 Given a single stranded DNA string, compute how many times each nucleotide occurs in the string.
 
-The genetic language of every living thing on the planet is DNA. 
-DNA is a large molecule that is built from an extremely long sequence of individual elements called nucleotides. 
+The genetic language of every living thing on the planet is DNA.
+DNA is a large molecule that is built from an extremely long sequence of individual elements called nucleotides.
 4 types exist in DNA and these differ only slightly and can be represented as the following symbols: 'A' for adenine, 'C' for cytosine, 'G' for guanine, and 'T' thymine.
 
 Here is an analogy:

exercises/palindrome-products/description.md

@@ -7,7 +7,7 @@ Given a range of numbers, find the largest and smallest palindromes which
 are products of numbers within that range.
 
 Your solution should return the largest and smallest palindromes, along with the
-factors of each within the range. If the largest or smallest palindrome has more 
+factors of each within the range. If the largest or smallest palindrome has more
 than one pair of factors within the range, then return all the pairs.
 
 ## Example 1

exercises/rectangles/description.md

@@ -35,27 +35,27 @@ The above diagram contains 6 rectangles:
 ```
 
 ```text
-       
-       
+
+
    +--+
    |  |
    +--+
 ```
 
 ```text
-       
-       
+
+
 +--+
 |  |
 +--+
 ```
 
 ```text
-       
-  ++   
-  ++   
-       
-       
+
+  ++
+  ++
+
+
 ```
 
 You may assume that the input is always a proper rectangle (i.e. the length of