Fix incorrect circle markups in some puzzles

[JohnHKoh]

toCellIndex requires number of columns, but the number of rows was being passed in, leading to the circles being the wrong place. Passing in grid[0].length fixes this. Addresses #122 and #183.

[vercel[bot]]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/downforacross/downforacross.com/GUjoj84TDGisw7KVYwbYvk1sSWVm
✅ Preview: https://downforacrossc-git-fork-johnhkoh-johnhkoh-fix-markup-ind-e24b9e.vercel.app

[frozenpandaman]

cool, thanks!