feat: kata/is-it-a-palindrome (#907)

* docs: kata description

* feat(8-kyu): kata/is-it-a-palindrome

* Trigger CI

---------

Co-authored-by: ParanoidUser <5120290+ParanoidUser@users.noreply.github.com>

Author: github-actions[bot]

kata/8-kyu/index.md

@@ -125,6 +125,7 @@
 - [Invert values](invert-values "5899dc03bc95b1bf1b0000ad")
 - [Is he gonna survive?](is-he-gonna-survive "59ca8246d751df55cc00014c")
 - [Is it a number?](is-it-a-number "57126304cdbf63c6770012bd")
+- [Is it a palindrome?](is-it-a-palindrome "57a1fd2ce298a731b20006a4")
 - [Is it even?](is-it-even "555a67db74814aa4ee0001b5")
 - [Is n divisible by x and y?](is-n-divisible-by-x-and-y "5545f109004975ea66000086")
 - [Is the string uppercase?](is-the-string-uppercase "56cd44e1aa4ac7879200010b")

kata/8-kyu/is-it-a-palindrome/README.md

@@ -0,0 +1,5 @@
+# [Is it a palindrome?](https://www.codewars.com/kata/is-it-a-palindrome "https://www.codewars.com/kata/57a1fd2ce298a731b20006a4")
+
+Write a function that checks if a given string (case-insensitive) is a [palindrome](https://en.wikipedia.org/wiki/Palindrome).
+
+A palindrome is a word, number, phrase, or other sequence of symbols that reads the same backwards as forwards, such as `madam` or `racecar`.

kata/8-kyu/is-it-a-palindrome/main/Palindrome.java

@@ -0,0 +1,5 @@
+interface Palindrome {
+  static boolean isPalindrome(String x) {
+    return new StringBuilder(x).reverse().toString().equalsIgnoreCase(x);
+  }
+}

kata/8-kyu/is-it-a-palindrome/test/SampleTests.java

@@ -0,0 +1,19 @@
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class SampleTests {
+  @ParameterizedTest
+  @ValueSource(strings = {"a", "aba", "Abba", "Bob", "Madam", "AbBa", ""})
+  void sample(String str) {
+    assertTrue(Palindrome.isPalindrome(str));
+  }
+
+  @ParameterizedTest
+  @ValueSource(strings = {"hello", "123521"})
+  void negative(String str) {
+    assertFalse(Palindrome.isPalindrome(str));
+  }
+}