Synced problem descriptions to problem specs. (#3499)

exercises/practice/darts/.docs/instructions.md

@@ -6,6 +6,8 @@ Write a function that returns the earned points in a single toss of a Darts game
 
 In our particular instance of the game, the target rewards 4 different amounts of points, depending on where the dart lands:
 
+![Our dart scoreboard with values from a complete miss to a bullseye](https://assets.exercism.org/images/exercises/darts/darts-scoreboard.svg)
+
 - If the dart lands outside the target, player earns no points (0 points).
 - If the dart lands in the outer circle of the target, player earns 1 point.
 - If the dart lands in the middle circle of the target, player earns 5 points.
@@ -16,8 +18,14 @@ Of course, they are all centered at the same point — that is, the circles are
 
 Write a function that given a point in the target (defined by its [Cartesian coordinates][cartesian-coordinates] `x` and `y`, where `x` and `y` are [real][real-numbers]), returns the correct amount earned by a dart landing at that point.
 
+## Credit
+
+The scoreboard image was created by [habere-et-dispertire][habere-et-dispertire] using [Inkscape][inkscape].
+
 [darts]: https://en.wikipedia.org/wiki/Darts
 [darts-target]: https://en.wikipedia.org/wiki/Darts#/media/File:Darts_in_a_dartboard.jpg
 [concentric]: https://mathworld.wolfram.com/ConcentricCircles.html
 [cartesian-coordinates]: https://www.mathsisfun.com/data/cartesian-coordinates.html
 [real-numbers]: https://www.mathsisfun.com/numbers/real-numbers.html
+[habere-et-dispertire]: https://exercism.org/profiles/habere-et-dispertire
+[inkscape]: https://en.wikipedia.org/wiki/Inkscape

exercises/practice/perfect-numbers/.docs/instructions.md

@@ -1,11 +1,10 @@
 # Instructions
 
-Determine if a number is perfect, abundant, or deficient based on
-Nicomachus' (60 - 120 CE) classification scheme for positive integers.
+Determine if a number is perfect, abundant, or deficient based on Nicomachus' (60 - 120 CE) classification scheme for positive integers.
 
 The Greek mathematician [Nicomachus][nicomachus] devised a classification scheme for positive integers, identifying each as belonging uniquely to the categories of **perfect**, **abundant**, or **deficient** based on their [aliquot sum][aliquot-sum].
 The aliquot sum is defined as the sum of the factors of a number not including the number itself.
-For example, the aliquot sum of 15 is (1 + 3 + 5) = 9
+For example, the aliquot sum of `15` is `1 + 3 + 5 = 9`.
 
 - **Perfect**: aliquot sum = number
   - 6 is a perfect number because (1 + 2 + 3) = 6

exercises/practice/resistor-color-trio/.docs/instructions.md

@@ -23,7 +23,7 @@ For this exercise, you need to know only three things about them:
 - Grey: 8
 - White: 9
 
-In `resistor-color duo` you decoded the first two colors.
+In Resistor Color Duo you decoded the first two colors.
 For instance: orange-orange got the main value `33`.
 The third color stands for how many zeros need to be added to the main value.
 The main value plus the zeros gives us a value in ohms.