docs(challenges): improvements to Constraints LaTeX/KaTeX syntax

challenges/cakes-swerc-2020-2021/README.md

@@ -27,7 +27,7 @@ available ingredients.
 
 ### Constraints
 
-- $$1 <= N <= 10$$
+- $$1 \leq N \leq 10$$
 - All ingredient quantities will be integers between 1 and 10 000.
 
 ## Source

challenges/offset-arrays/README.md

@@ -24,7 +24,7 @@ You are given a list of `n` array definitions and your job is to figure out what
 
 ### Constraints
 
-- $$1 <= n <= 100$$
+- $$1 \leq n \leq 100$$
 - Array names consist only of uppercase letters A to Z.
 - Array lengths are between 1 and 100 (no empty arrays).
 - Indexing operations have at most 50 levels of nesting.

challenges/single-number/README.md

@@ -10,8 +10,8 @@ You must implement a solution with a linear runtime complexity and use only cons
 
 ### Constraints
 
-- $$1 <= numbers.length <= 3 \times 10^4$$
-- $$-3 \times 10^4 <= numbers[index] <= 3 \times 10^4$$
+- $$1 \leq numbers.length \leq 3 \times 10^4$$
+- $$-3 \times 10^4 \leq numbers[index] \leq 3 \times 10^4$$
 - Each element in the array appears twice except for one element which appears only once.
 
 ## Source

challenges/sorting-algorithms/README.md

@@ -11,12 +11,12 @@ Write a function that takes a list of integers and sort them in ascending order.
 
 ## Input
 
-- **Line 1:** An integer `n` for the length of the list of integers
-- **`n` next lines:** the numbers to sort
+- **Line 1:** An integer $n$ for the length of the list of integers
+- **$n$ next lines:** the numbers to sort
 
 ### Constraints
 
-- List of integers length <= 25 000
+- $$n \leq 25 000$$
 
 ## Source