Add instructions for installing custom songs to Trombone Champ: Unflattened on Steam (#50)

* add instructions for installing songs for TCU Steam

* wording

Author: DerpyChap

docs/files/vr/copychartsteam.png

@@ -1,9 +1,11 @@
 - **User Guide**
 - [Introduction](./)
-- **Modding**
+- **Modding Trombone Champ**
 - [Using r2modman](installing-r2modman)
 - [Installing Songs](installing-songs)
 - [Upgrading to TrombLoader 2](migrating-to-v2)
+- **Modding Trombone Champ: Unflattened**
+- [Installing Songs (SteamVR)](installing-songs-steamvr)
 - **Charting**
 - [Creating Charts](creating-charts)
 - [Charting Guidelines](charting-guidelines)

docs/files/vr/ingamesteam.png

@@ -0,0 +1,33 @@
+# Installing Songs (Steam Version)
+---
+!> **IMPORTANT:** This guide is for the VR game *Trombone Champ: Unflattened* on **Steam**. For installing custom songs in the standard game, see the [mod installation guide for Trombone Champ](installing-r2modman).
+
+Trombone Champ: Unflattened has built-in custom song support, and is compatible with charts made for the base game. Do note that only video and image backgrounds will work, custom backgrounds made in Unity will not.
+
+?> You can find community made custom charts on [TootTally](https://toottally.com/), or by browsing [TromboneDB](https://tc-mods.github.io/TromboneDB/).
+
+1. Open Steam and select **Trombone Champ: Unflattened**. Click the ⚙️ **Cog Wheel** icon and go to **Manage > Browse local files**.
+![Browse local files in Steam](../docs/files/vr/unflattenedsteam.png)
+
+2. From here, navigate to `TromboneChampUnflattened_Data\StreamingAssets\customtracks\`. In another window or tab, open up the ZIP file containing the chart you downloaded, and then drag the containing folder into the `customtracks` folder.
+
+![Browse local files in Steam](../docs/files/vr/copychartsteam.png)
+
+!> Each chart must be stored in its own folder. If the ZIP file you've downloaded doesn't contain a folder, you will have to make one yourself and then copy the ZIP contents (`song.tmb`, `song.ogg`, and `.bg.png`/`.bg.mp4`) to it.
+
+3. Once you've finished copying over the songs you want, start up the game, head into **Free Play**, and then you'll find your custom songs listed in their own category.
+
+![Custom song shown in-game](../docs/files/vr/ingamesteam.png)
+
+## Finding Songs
+
+There are a number of places you can find Trombone Champ custom songs online. Here are a few options:
+- The search function on the [TootTally website](https://toottally.com/search/).
+- [TromboneDB](https://tc-mods.github.io/TromboneDB/) has an archive of the majority of charts released, including charts that are too large for TootTally.
+- The `#custom-charts` channel in the [Trombone Champ Modding Discord](https://discord.gg/KVzKRsbetJ).
+- The Tootbender bot's chart search command in the [Trombone Champ Modding Discord](https://discord.gg/KVzKRsbetJ).
+- Most charts have showcase videos on YouTube. Sometimes they will have download links in the description.
+
+### Creating Custom Songs {docsify-ignore}
+
+> Check out the [**Charting guide**](creating-charts) for info on creating your own custom charts.

docs/files/vr/unflattenedsteam.png

@@ -66,10 +66,9 @@ Now, you may have run into an issue where your song came up, but instead of a do
 There are a number of places you can find Trombone Champ custom songs online. Here are a few options:
 - TootTally's in-game song downloader. Note that not all charts may be available for download in-game.
 - The search function on the [TootTally website](https://toottally.com/search/). Any results you get here will likely be the same as what the in-game song downloader would have.
+- [TromboneDB](https://tc-mods.github.io/TromboneDB/) has an archive of the majority of charts released, including charts that are too large for TootTally.
 - The `#custom-charts` channel in the [Trombone Champ Modding Discord](https://discord.gg/KVzKRsbetJ).
 - The Tootbender bot's chart search command in the [Trombone Champ Modding Discord](https://discord.gg/KVzKRsbetJ).
-- ~~TheGlitched64's [spreadsheet containing information on every custom chart](https://docs.google.com/spreadsheets/d/1xpoUnHdSJFqOQEK_637-HCECYtJsgK91oY4dRuDMtik/edit?usp=sharing).~~
-  - Discord has since disabled the ability to link files externally, so most links in the spreadsheet will no longer work. We have created [TromboneDB](https://tc-mods.github.io/TromboneDB/) as a replacement which has download mirrors for all charts.
 - Most charts have showcase videos on YouTube. Sometimes they will have download links in the description.
 
 ### Creating Custom Songs {docsify-ignore}

docs/sidebar.md

@@ -47,6 +47,7 @@
                 '/installing-r2modman': '/docs/user-guide/installation/installing-r2modman.md',
                 '/installing-r2modman-linux': '/docs/user-guide/installation/installing-r2modman-linux.md',
                 '/migrating-to-v2': '/docs/user-guide/installation/migration.md',
+                '/installing-songs-steamvr': '/docs/user-guide/installation/installing-songs-steamvr.md',
                 '/creating-charts': '/docs/user-guide/charting/creating-charts.md',
                 '/charting-guidelines': '/docs/user-guide/charting/charting-guidelines.md',
                 '/chart-backgrounds': '/docs/user-guide/charting/chart-backgrounds.md',