feat: Mercedes Lesson04 ReadMe (#147)

Author: mercedes-mathews

lesson_04/mercedesmathews/README.md

@@ -0,0 +1,55 @@
+## Python implementation
+```python
+def is_prime(num):
+    if num < 2:
+        return False
+    else:
+        for i in range(2, int(num ** 0.5) + 1):  
+            if num % i == 0:
+                return False 
+        return True 
+```
+
+## JavaScript implementation
+```javascript
+function isPrime(num) {
+  if (num < 2) {
+    return false;
+  } else {
+    for (let i = 2; i * i <= num; i++) {
+        if (num % i === 0) {
+          return false;
+        }
+    }
+    return true;
+  }
+}
+```
+
+## Explanation
+The Python implementation uses a function named `is_prime` and takes a single argument `num` and returns `true` if the number is a prime number (i.e., when the number is only divisible by 1 and itself), otherwise, it returns `false`.
+
+The JavaScript implementation uses a function named `isPrime` and takes a single argument `num` and returns `True` if the number is a prime number (i.e., when the number is only divisible by 1 and itself), otherwise, it returns `False`.
+
+
+### Similarities
+- Input
+    - Both languages don't need the parameter datatype declared.
+
+- Conditionals
+    - Both languages have `if` and `else` statements.
+
+### Differences
+- Syntax:
+    - To define a function, Python uses the keyword `def` while JavaScript uses the keyword `function`.
+    - Python uses a colon `:` and indentation to determine code blocks, while JavaScript uses curly brackets `{}`.
+    - JavaScript uses a semicolon `;` at the end of a statement.
+
+- Input/Output:
+    - Python's boolean values are `True` and `False`, while JavaScript's are `true` and `false`.
+    - To print output, Python uses `print()`, while JavaScript uses `console.log()`.
+
+- Conditionals and Loops
+    - JavaScript has an `else if` statement, while Python has an `elif` statement.
+    - JavaScript `for loops` have three expressions to determine loop, while Python loops based off a given range.
+