Docs Fixes: Developer Guide Steps Are Not Reproducible

[josiahg]

Would submit a PR myself but not sure of the "correct" updates here.

From developer-guide.md:

mage build:linux && mage reloadPlugin

This only compiles dist/gfx_github_linux_amd64 and will cause the plugin to fail to load if your local or Docker image are using a different architecture - IE arm64 which is what happens on my M1 machine when I docker-compose up.

Fixed by running mage -v which compiles for all architectures in my case.

Also from developer-guide.md:

Alternatively, you can have yarn watch for changes and automatically recompile them.

yarn watch

This fails with error Command "watch" not found.. Fixed by simply using yarn dev but the frustration of following the steps and getting errors persists. :)