Update footer urls in solution template

Author: ggeerraarrdd

src/main/templates/solution.txt

@@ -31,5 +31,5 @@ Difficulty per Site: {{ difficulty }}
 
 {{ nb }}
 -->
-Go to [Table of Contents](/README.md#contents)
-Go to [Overview](/README.md){{ lastline }}
+Go to [Index](../?tab=readme-ov-file#index)\
+Go to [Overview](../?tab=readme-ov-file){{ lastline }}