Add a 40mm Acid Inventory Sprite. (Sprite included)

[Crazyjr20]

I assume it was forgotten or more important things took priority as it was prior to 1.0, but the 40mm acid grenade lacks an inventory sprite and instead uses its regular sprite which is at horizontal angle unlike every other 40mm. And while its not noticable in game, its also lower res than inventory sprites.

This isn't a gamebreaking issue obviously but it is inconsistent with every other 40mm grenade and everytime I look it at it reminds me.

I have actually already made a sprite myself because the sprite suggests its just a recoloured regular 40mm grenade and as such was easy to make. I'll leave it right here if you want this one:

I can also provide the modified 40mmchemgrenade xml alongside InventoryIconAtlas2.png edited to have it included if desired.

This was already brought up here, but I've provided half the solution to Wheatley's issue in my post.
#11241 (comment)