feat: add proton config info

docs/astro.config.mjs

@@ -32,6 +32,10 @@ export default defineConfig({
               label: "Install",
               autogenerate: { directory: "user/install" },
             },
+            {
+              label: "Usage",
+              items: [{ slug: "user/usage/proton" }],
+            },
           ],
         },
         {

docs/src/content/docs/user/usage/proton.mdx

@@ -0,0 +1,62 @@
+---
+title: Proton
+description: Use Proton to run your Windows game on Linux at near-native speeds.
+---
+
+Drop's Proton configuration depends on:
+
+- UMU launcher (more specifically the `umu-run` binary)
+- **another application** to download and manage Proton versions
+
+## Installing UMU launcher
+
+Install UMU launcher through their own guide on [their GitHub repo](https://github.com/Open-Wine-Components/umu-launcher?tab=readme-ov-file#packaging). It covers packaging for a variety of distro. If you're not covered, give it a Google search, or open an issue on GitHub or Discord and we'll try to help you.
+
+To check it's installed, try running `umu-run` from your terminal.
+
+:::note
+If you're using Distrobox, it might be a little more complicated to install.
+
+If you've installed it **outside** of Distrobox (recommended), it should work out of the box.
+
+If you've install it **inside** of Distrobox, you'll have to export it, and figure out how to pass through your GPU and drivers.
+:::
+
+## Downloading other Proton versions
+
+You can download other Proton versions from a variety of sources:
+
+- Directly from the project, typically in a GitHub release
+- Through Steam, which downloads official Proton versions
+- 3rd-party application
+
+For the 3rd-party application, we recommend [ProtonUp-Qt](https://github.com/DavidoTek/ProtonUp-Qt), an open-source GUI application that supports quite a few different versions of Proton.
+
+## Detecting Proton versions
+
+Drop searches the following places for Proton versions:
+
+- `/usr/share/steam/compatibilitytools.d/`
+- `~/.steam/root/compatibilitytools.d/`
+
+Most applications support reading and writing to these directories for Proton versions, as they're Steam directories.
+
+Drop can also pick up other Proton versions, if you manually add them.
+
+:::note
+To be discovered by Drop, the folder you provide, or any folder in one of the above directories **must**:
+
+- have the `proton` binary
+- have a `compatibilitytool.vdf` file
+
+:::
+
+## Using Proton versions
+
+:::caution
+To launch any Windows game, you **must** first set a default Proton version.
+:::
+
+Drop uses a global default Proton version to launch games by default. You can override this in a game's options. 
+
+![Screenshot showing how to override the proton version](./proton-options-override.png)