Docs: add landing page

docs/README.md

@@ -0,0 +1,31 @@
+# 32blit SDK
+
+OS specific docs, these cover setup and command-line builds:
+
+* [Linux](Linux.md)
+* [Linux - ChromeOS](ChromeOS.md)
+* [Windows](Windows.md)
+* [Windows - WSL (Advanced)](Windows-WSL.md)
+* [macOS](macOS.md)
+
+If you want to run in a browser, refer to the [Emscripten docs](Emscripten.md)
+
+How to set up your editor:
+
+* [Visual Studio Code](VSCode.md)
+
+# Building for 32blit
+
+If you want to run on the 32blit handheld, refer to the [32blit docs](32blit.md)
+
+# Building for PicoSystem
+
+If you want to run on the PicoSystem handheld or other RP2040-based setups, refer to the [Pico docs](pico.md)
+
+# Boilerplate
+
+To get started writing your own game, you should use the 32blit boilerplate - https://github.com/32blit/32blit-boilerplate/
+
+## Help & Support
+
+Join the 32blit community on Discord - https://discord.gg/7qM9ftC