December 2025 practice exercise docs sync. (#4058)

Pulled in latest exercise introductions and instructions from problem-specifications.

Author: BethanyG

exercises/practice/killer-sudoku-helper/.docs/instructions.md

@@ -74,7 +74,7 @@ You can also find Killer Sudokus in varying difficulty in numerous newspapers, a
 
 ## Credit
 
-The screenshots above have been generated using [F-Puzzles.com](https://www.f-puzzles.com/), a Puzzle Setting Tool by Eric Fox.
+The screenshots above have been generated using F-Puzzles.com, a Puzzle Setting Tool by Eric Fox.
 
 [sudoku-rules]: https://masteringsudoku.com/sudoku-rules-beginners/
 [killer-guide]: https://masteringsudoku.com/killer-sudoku/

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

@@ -1,79 +1,47 @@
 # Instructions
 
-Given a 3 x 4 grid of pipes, underscores, and spaces, determine which number is represented, or whether it is garbled.
+Optical Character Recognition or OCR is software that converts images of text into machine-readable text.
+Given a grid of characters representing some digits, convert the grid to a string of digits.
+If the grid has multiple rows of cells, the rows should be separated in the output with a `","`.
 
-## Step One
+- The grid is made of one of more lines of cells.
+- Each line of the grid is made of one or more cells.
+- Each cell is three columns wide and four rows high (3x4) and represents one digit.
+- Digits are drawn using pipes (`"|"`), underscores (`"_"`), and spaces (`" "`).
 
-To begin with, convert a simple binary font to a string containing 0 or 1.
+## Edge cases
 
-The binary font uses pipes and underscores, four rows high and three columns wide.
+- If the input is not a valid size, your program should indicate there is an error.
+- If the input is the correct size, but a cell is not recognizable, your program should output a `"?"` for that character.
 
-```text
-     _   #
-    | |  # zero.
-    |_|  #
-         # the fourth row is always blank
-```
+## Examples
 
-Is converted to "0"
-
-```text
-         #
-      |  # one.
-      |  #
-         # (blank fourth row)
-```
-
-Is converted to "1"
-
-If the input is the correct size, but not recognizable, your program should return '?'
-
-If the input is the incorrect size, your program should return an error.
-
-## Step Two
-
-Update your program to recognize multi-character binary strings, replacing garbled numbers with ?
-
-## Step Three
-
-Update your program to recognize all numbers 0 through 9, both individually and as part of a larger string.
-
-```text
- _
- _|
-|_
-
-```
-
-Is converted to "2"
+The following input (without the comments) is converted to `"1234567890"`.
 
 ```text
       _  _     _  _  _  _  _  _  #
-    | _| _||_||_ |_   ||_||_|| | # decimal numbers.
+    | _| _||_||_ |_   ||_||_|| | # Decimal numbers.
     ||_  _|  | _||_|  ||_| _||_| #
-                                 # fourth line is always blank
+                                 # The fourth line is always blank,
 ```
 
-Is converted to "1234567890"
-
-## Step Four
+The following input is converted to `"123,456,789"`.
 
-Update your program to handle multiple numbers, one per line.
-When converting several lines, join the lines with commas.
+<!-- prettier-ignore-start -->
 
 ```text
-    _  _
+    _  _ 
   | _| _|
   ||_  _|
-
-    _  _
-|_||_ |_
+         
+    _  _ 
+|_||_ |_ 
   | _||_|
-
- _  _  _
+         
+ _  _  _ 
   ||_||_|
   ||_| _|
-
+         
 ```
 
-Is converted to "123,456,789".
+<!-- prettier-ignore-end -->

exercises/practice/ocr-numbers/.docs/introduction.md

@@ -0,0 +1,6 @@
+# Introduction
+
+Your best friend Marta recently landed their dream job working with a local history museum's collections.
+Knowing of your interests in programming, they confide in you about an issue at work for an upcoming exhibit on computing history.
+A local university's math department had donated several boxes of historical printouts, but given the poor condition of the documents, the decision has been made to digitize the text.
+However, the university's old printer had some quirks in how text was represented, and your friend could use your help to extract the data successfully.

exercises/practice/triangle/.docs/instructions.md

@@ -14,7 +14,8 @@ A _scalene_ triangle has all sides of different lengths.
 For a shape to be a triangle at all, all sides have to be of length > 0, and the sum of the lengths of any two sides must be greater than or equal to the length of the third side.
 
 ~~~~exercism/note
-We opted to not include tests for degenerate triangles (triangles that violate these rules) to keep things simpler.
+_Degenerate triangles_ are triangles where the sum of the length of two sides is **equal** to the length of the third side, e.g. `1, 1, 2`.
+We opted to not include tests for degenerate triangles in this exercise.
 You may handle those situations if you wish to do so, or safely ignore them.
 ~~~~