Half-Life Splash Texts

Adds 124 Half-Life related splash texts!\ \ These are mostly in-game dialogue, as well as a handful of references to the community.\ This is entirely based on Half-Life 1.\ All texts have a similar style to the quirky messages in vanilla.\ \ A complete list can be found [here](https://pastebin.com/dUF0wJPA).\ \ \ \ \ \ Side note: I don't know much about the Half-Life series, so the references may be limited. I just like the silly scientist dialogue.