Provide more details on runtime directory

[aryzing]

Provides more details on what to do with the runtime directory.

[David-Else]

Thanks for the update, but I don't think:

searched by 'hx'

is very clear or grammatically correct. How about something more like the following, maybe you could use some or all of it?

Download the pre-built binaries from the GitHub Releases page. The downloaded tarball includes an hx binary and a runtime directory. To set up Helix:

1. Add the hx binary to your system's $PATH to allow it to be used from the command line.
2. Copy the runtime directory to a location that hx searches for runtime files. A typical location on Linux/macOS is ~/.config/helix/runtime.

To see the runtime directories that hx searches, run hx --health. If necessary, you can override the default runtime location by setting the HELIX_RUNTIME environment variable.

[aryzing]

It's great, will use all of it