Add Day 10 and Day 11 solutions

Day 10: Indicator light configuration with bitmask brute-force
Day 11: Graph path counting with memoized DFS
- Part 1: Count all paths from 'you' to 'out'
- Part 2: Count paths from 'svr' to 'out' visiting both 'dac' and 'fft'

data/examples/11-2.txt

@@ -0,0 +1,14 @@
+svr: aaa bbb
+aaa: fft
+fft: ccc
+bbb: tty
+tty: ccc
+ccc: ddd eee
+ddd: hub
+hub: fff
+eee: dac
+dac: fff
+fff: ggg hhh
+ggg: out
+hhh: out
+