update docs content (#11374)

Move all docs to zed repo

Release Notes:

- N/A

---------

Co-authored-by: Marshall Bowers <elliott.codes@gmail.com>
Co-authored-by: Marshall <marshall@zed.dev>

docs/src/developing-zed.md

@@ -0,0 +1,16 @@
+# Developing Zed
+
+See the platform-specific instructions for building Zed from source:
+
+- [macOS](./development/macos.md)
+- [Linux](./development/linux.md)
+- [Windows](./development/windows.md)
+
+If you'd like to develop collaboration features, additionally see:
+
+- [Local Collaboration](./development/local-collaboration.md)
+
+## Contributor links
+
+- [Releases](./development/releases.md)
+- [Debugging Crashes](./development/debugging-crashes.md)