The idea was to create a way for the player to have a terrain that they can modify at run time.
If you want to have a look at the code behind this destruction, it's available here: https://gist.github.com/Westerveld/c0cf2fc3fe005e9f387e6769ad2a95a9
The idea is to do the following:
Get the direction we are facing
Raycast in that direction
Check if the raycast is colliding with an object that has a tilemap
If it does, we remove the tile at the location where the collision happened. We make sure to floor the float as the tile anchor points are at the bottom left. i.e. if we raycast to the position (0.9,1.5), we want to destroy the tile at (0,1)