feat: add javascript solution to lc problem: No.1290.Convert Binary Number in a Linked List to Integer (doocs#413)

Author: zhaocchen

solution/1200-1299/1290.Convert Binary Number in a Linked List to Integer/README.md

@@ -120,6 +120,31 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {number}
+ */
+var getDecimalValue = function(head) {
+    let res = 0;
+    while (head !== null) {
+        res *= 2;
+        if (head.val) res += 1;
+        head = head.next;
+    }
+    return res;
+};
+```
+
 ### **...**
 
 ```

solution/1200-1299/1290.Convert Binary Number in a Linked List to Integer/README_EN.md

@@ -131,6 +131,31 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {number}
+ */
+var getDecimalValue = function(head) {
+    let res = 0;
+    while (head !== null) {
+        res *= 2;
+        if (head.val) res += 1;
+        head = head.next;
+    }
+    return res;
+};
+```
+
 ### **...**
 
 ```

solution/1200-1299/1290.Convert Binary Number in a Linked List to Integer/Solution.js

@@ -0,0 +1,20 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val) {
+ *     this.val = val;
+ *     this.next = null;
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {number}
+ */
+ var getDecimalValue = function(head) {
+    let res = 0;
+    while (head !== null) {
+        res *= 2;
+        if (head.val) res += 1;
+        head = head.next;
+    }
+    return res;
+};