feat: adds Linda's isPrime implementation and write-up (#269)

Author: lquinoa252

lesson_04/lindaquinoa/README.md

@@ -0,0 +1,54 @@
+## Java implementation
+
+```java
+public class PrimeCheck {
+    public static boolean isPrime(int n) {
+        if (n < 2) return false;
+        for (int i = 2; i <= Math.sqrt(n); i++) {
+            if (n % i == 0) return false;
+        }
+        return true;
+    }
+
+    public static void main(String[] args) {
+        int number = 29;
+        System.out.println(number + " is prime? " + isPrime(number));
+    }
+}
+```
+
+## TypeScript implementation
+
+```TypeScript
+function isPrime(n: number): boolean {
+    if (n < 2) return false;
+    for (let i = 2; i <= Math.sqrt(n); i++) {
+        if (n % i === 0) return false;
+    }
+    return true;
+}
+
+const number = 29;
+console.log(`${number} is prime? ${isPrime(number)}`);
+```
+
+## Explanation
+
+The Java implementation uses a function named 'isPrime' that is defined inside a 'class'. It takes a single integer as input and returns 'true' if the number is prime (i.e., greater than 1 and not divisible by any number other than 1 and itself). Otherwise, it returns 'false'.
+
+The TypeScript implementation also defines a function named 'isPrime' that accepts a number as input. It uses the same mathematical logic as the Java function, returning 'true' when the number is prime and 'false' otherwise.
+
+### Differences
+
+1. **Syntax**:
+
+    -In Java, functions must be defined inside a class, and you must also create a 'main' method to run the program.
+    -In TypeScript, functions can be written directly without needing a 'class' or a special entry point.
+
+2. **Types**:
+    -Java requires explicit type declarations ('int' for integers, 'boolean' for return values).
+    -TypeScript also uses types, but the syntax is lighter (e.g., 'n: number' instead of 'int n').
+
+3. **Structure**:
+     -Java enforces more boilerplate code, such as the 'public class' and 'public static' keywords.
+    -TypeScript feels closer to JavaScript and allows quicker setup with just the function and a 'console.log' statement.