Write the SteamTools on Linux installation guide

Author: SobakinTech

docs/beginners_guide/installing_steamtools.md

@@ -14,8 +14,24 @@ description: ""
 **SteamTools isn't officially supported on Linux.** We can't help with any issues you have while using it on Linux.
 :::
 
-:::info
-The Linux SteamTools installation guide is a WIP. [Help us write this!](https://github.com/Manifestor-cc/usage-guide/issues/5)
+1. Install [PortProton](https://flathub.org/en/apps/ru.linux_gaming.PortProton) (Only available via Flatpak)
+2. Open PortProton and wait for it to finish installing
+3. Find "Steam (UNSTABLE)" in the AUTOINSTALLS tab and click on it
+:::note
+The PortProton window may dissapear entirely for a minute, just give it a moment.
 :::
+4. Once the "Choices" window pops up, just click CREATE SHORTUCT
+5. On the second popup, click LAUNCH. Wait until the Steam login window pops up
+6. Login with your Steam account
+7. [Download the SteamTools installer](https://steamtools.net/res/st-setup-1.8.17r2.exe)
+8. Right-click the installer, click Open With.. and select PortProton
+9. In the popup, select LAUNCH
+10. Go through all of the installation steps (just click Next you don't have to change anything)
 
-Use [PortProton](https://flathub.org/en/apps/ru.linux_gaming.PortProton) to run SteamTools & Steam
+:::note
+When you exit SteamTools for the first time, a "Choices" window will open. Just click CREATE SHORTCUT
+:::
+
+:::important
+To launch Steam or SteamTools, use the PortProton app. (If SteamTools doesn't appear as an option, relaunch the app)
+:::