Add features to readme. (#41)

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## Description
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* Add notable features.
* Add check for latest SC64 firmware.

## Motivation and Context
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## Types of changes
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- [ ] Improvement (non-breaking change that adds a new feature)
- [ ] Bug fix (fixes an issue)
- [ ] Breaking change (breaking change)
- [ ] Config and build (change in the configuration and build system,
has no impact on code or features)

## Checklist:
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- [ ] My code follows the code style of this project.
- [ ] My change requires a change to the documentation.
- [ ] I have updated the documentation accordingly.
- [ ] I have added tests to cover my changes.
- [ ] All new and existing tests passed.

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README.md

@@ -1,5 +1,5 @@
 # N64 Flashcart Menu
-**This repo and its documentation is currently experimental and subject to change without notice.**
+An open source menu for N64 flashcarts.
 
 ## Aims
 * Support as many N64 FlashCarts as possible.
@@ -9,13 +9,26 @@
 * Support as many common mods and features as possible.
 
 
+## Current (notable) menu features
+* Fully Open Source.
+* Loads all known N64 games (including iQue and byteswapped ROMs).
+* Emulator support (GB, GBC, NES) ROMs.
+* N64 ROM box image support.
+* Background image (PNG) support.
+* Comprehensive ROM save database (including HomeBrew headers).
+* Comprehensive ROM information display.
+* Real Time Clock support.
+* Music playback (MP3).
+
+
 ## Getting started
 
 ### SC64
+Ensure the cart is running the latest [firmware](https://github.com/Polprzewodnikowy/SummerCart64/releases/latest)
 Download the `sc64menu.n64` ROM from the latest action run assets.
 Add it to the root folder on your SD card.
 
-### ED64
+### ED64 & ED64P
 Currently not supported, but there is an aim to do so.
 The aim is to replace [Altra64](https://github.com/networkfusion/altra64) and [ED64-UnofficialOS](https://github.com/n64-tools/ED64-UnofficialOS-binaries).