fix: link from PGF 6 to PGF 7

Author: djcarter85

src/_posts/2025-11-16-PGF-06.md

@@ -333,5 +333,6 @@ Backtracker algorithm.
 
 One thing you might have spotted is that, unlike the previous two algorithms,
 Recursive Backtracker doesn't rely on using a rectangular grid: all that matters
-is that we know which cells are neighbours. In the next post we'll investigate
-drawing mazes on more interesting-looking grids.
+is that we know which cells are neighbours. In [the next
+post](/2026/01/26/PGF-07) we'll investigate drawing mazes on more
+interesting-looking grids.