feat(8.1): finish unit 8 lesson 1 activities

src/main/java/Unit8/U8_L1_Activity_One.java

@@ -0,0 +1,16 @@
+package Unit8;
+
+// Have to get rid of package statement
+
+public class U8_L1_Activity_One {
+
+    public static int sumOfDiag(int[][] arr) {
+        int sum = 0;
+        for (int i = 0; i < arr.length && i < arr[i].length; i++) {
+            sum += arr[i][i];
+        }
+
+        return sum;
+    }
+
+}

src/main/java/Unit8/U8_L1_Activity_Two.java

@@ -0,0 +1,18 @@
+package Unit8;
+
+// Have to get rid of package statement
+
+public class U8_L1_Activity_Two {
+
+    public static int[][] productTable(int rows, int cols) {
+        int[][] table = new int[rows][cols];
+
+        for (int i = 0; i < rows; i++) {
+            for (int j = 0; j < cols; j++) {
+                table[i][j] = i * j;
+            }
+        }
+
+        return table;
+    }
+}