Made README More Inviting

- added a slideshow gif of some in game images
- added some details about what the project is, and the major accomplishments
- added some hyperlinks to various pages for easy access

Fixes #229

README.md

@@ -3,6 +3,23 @@
 
 A demake of Portal for the Nintendo 64.
 
+## Overview
+
+This project aims to reproduce valve's original portal, playable on the N64. [Releases](https://github.com/lambertjamesd/portal64/releases) of this game are fully playable N64 ROM's that can either be played through an emulator or on a physical N64 game cartridge. Please follow specific release instructions to get ROM running on your target hardware.  Because this demake has been in development for many years, it has made significant progress in both gameplay systems and fidelity including: 
+- Twelve+ test chambers completed
+- Fully functioning portals, and gun
+- Fully functioning physics engine
+- Lighting system
+- Main/pause menus
+- Sound effects/dialogue
+- Cutscenes
+- Much more!
+
+This is a community driven project that welcomes any and all game testers and or [Contributors](./CONTRIBUTING.md). Updates are constantly being made to the game, so we recommend checking out the author's [YouTube Channel](https://www.youtube.com/@happycoder1989) for the latest updates.
+
+![](./assets/images/readme_slideshow.gif)
+
+
 ## How to build
 
 First, you will need to setup [Modern SDK](https://crashoveride95.github.io/n64hbrew/modernsdk/startoff.html).