Basic touch input added

Over the past week, I got a pretty funny feature request. Someone sent me a video of them trying to play the game in a Tesla!

The issue: one feature in the game requires you to "right click" to inspect unit stats, an important part of the game and also an unskippable part of the tutorial.

Although perhaps not on the top of my priority list, I decided to take a week off to try and adding touch support to my game. Thankfully, it was easier than I thought! 

As a quick fix to the right click issue, I added an extra button that appears only when the game has not detected any explicit mouse activity. If so, you can now use the "inspection mode" (the magnifying glass icon on the right) which lets you click on units and buttons in the shop without interacting with them, meaning you no longer have to right click:

I stole this idea another awesome mobile game that had a similar feature, shattered pixel dungeon.

That said, I don't want to announce total mobile support just yet. I already know that the game does not work on my own mobile phone via the browser at the moment (though some people in the discord reported that they can play it on their phones), aside from the fact that many ui elements are probably a bit small to be used on mobile. My #1 priority remains providing a fun experience on PC at the moment.

Hope this was a fun read, might make more of these if people enjoy them...