Add some explanation

README.md

@@ -1,7 +1,23 @@
 # Xtreme-Apps
 Bundle of external apps tweaked for Xtreme
 
-### Setup branch upstream remotes:
-```sh
-git config --local include.path ../.gitremotes
-```
+### Why?
+Apps we use for Xtreme are all modified (some lots more than others). This includes:
+- Removing duplicate icons that are part of firmware to **support our Asset Packs system**
+- Removing duplicate keyboard implementations to **use our extended system keyboard**
+- With our system keyboard also **support our CLI command `input keyboard`** to type with PC keyboard
+- **Moving location of save files** or changing how they are saved
+- **Changing application display names** to fit our scheme
+- **Changing how some menus work/look** or adding **new exclusive menus and features**
+- **Improving or extending functionality** and better integrating with Xtreme firmware
+- **Updating and fixing apps** that were abandoned by the original developers
+
+### How?
+**Apps made by the Xtreme team are just kept as code in the main branch. Others instead come from elsewhere and need tweaks applied.**
+Due to how Git works we can't just make edits in a submodule and publish it as a signle repo like that.
+Our changes need to be committed and tracked somewhere, but we didn't want to have a fork repo for each app.
+Instead we use **fork *branches*:tm:** where the **code for the apps is in branches** of this same repo and the **main branch has submodules to other branches** this same repo.
+As for pulling updates from the upstream repositories, remotes are not kept when pushing and cloning, so we use a modular system:
+- set it up by running `git config --local include.path ../.gitremotes` (this makes your git config import the file `.gitremotes`)
+- each app branch has a `.gitremotes` file which contains configuration for its `upstream` remote
+- this also has an alias for merging upstream updates with the correct ref by `git merge-upstream`