refactored the prb page and added fib seqq

problems/fibonacisequence/manifest.json

@@ -0,0 +1,6 @@
+{
+    "title": "Fibonacci Sequence",
+    "description": "Calculate the n-th Fibonacci number using a function. The Fibonacci sequence is defined as follows: F(0) = 0, F(1) = 1, and F(n) = F(n-1) + F(n-2) for n > 1.",
+    "description_md": "problems/fibonacisequence/description.md",
+    "test_code": "problems/fibonacisequence/test.py"
+}