Link to AoC problem in day module

src/Years/Y2015/Day1.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 1
+# [Year 2015 Day 1](https://adventofcode.com/2015/day/1)
 
 Pretty simple, basic warmup problem, nothing really novel is on display here
 except the effectful part computations.

src/Years/Y2015/Day10.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 10
+# [Year 2015 Day 10](https://adventofcode.com/2015/day/10)
 
 This day doesn't really add anything new, but we will show off our new views for
 viewing integers as lists of digits.

src/Years/Y2015/Day11.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 11
+# [Year 2015 Day 11](https://adventofcode.com/2015/day/11)
 
 This day provides a gentle introduction to refinement types, types which augment
 other types with a predicate that must hold for all the values of the refined

src/Years/Y2015/Day2.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 2
+# [Year 2015 Day 2](https://adventofcode.com/2015/day/2)
 
 This day provides us our first little taste of effectful parsing
 

src/Years/Y2015/Day3.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 3
+# [Year 2015 Day 3](https://adventofcode.com/2015/day/3)
 
 This day provides a gentle introduction to `mutual` blocks and mutually
 recursive functions.

src/Years/Y2015/Day4.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 4
+# [Year 2015 Day 4](https://adventofcode.com/2015/day/4)
 
 This day introduces us to a little bit of FFI, linking to openssl to use it's
 `MD5` functionality.

src/Years/Y2015/Day5.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 5
+# [Year 2015 Day 5](https://adventofcode.com/2015/day/5)
 
 This day provides a nice chance to introduce
 [views](https://idris2.readthedocs.io/en/latest/tutorial/views.html),

src/Years/Y2015/Day6.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 6
+# [Year 2015 Day 6](https://adventofcode.com/2015/day/6)
 
 <!-- idris
 module Years.Y2015.Day6

src/Years/Y2015/Day7.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 7
+# [Year 2015 Day 7](https://adventofcode.com/2015/day/7)
 
 This day provides us a gentle introduction to dependent maps.
 

src/Years/Y2015/Day8.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 8
+# [Year 2015 Day 8](https://adventofcode.com/2015/day/8)
 
 This day provides a more in depth introduction to writing effectful parsers,
 making use of state and non-determinism in our parsers.

src/Years/Y2015/Day9.md

@@ -1,4 +1,4 @@
-# Year 2015 Day 9
+# [Year 2015 Day 9](https://adventofcode.com/2015/day/9)
 
 This day provides our first example of a graph traversal problem. We'll use a
 `Choose` based effectful breath first search to identify all the possible paths