chore: allow users to set the REG_PORT for make dev using a envvar

[waveywaves]

Changes

On Apple Macs the ControlCenter listens on port 5000.

# lsof without running the docker registry locally
lsof -i :5000 
                                                      
COMMAND     PID         USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
ControlCe 81715 vibhavbobade   11u  IPv4 0xf70fc252883ced3a      0t0  TCP *:commplex-main (LISTEN)
ControlCe 81715 vibhavbobade   12u  IPv6 0x13b6e0db93572d28

I wanted to use the 5001 port instead to avoid unauthorized errors while running ko builds.

This change we ensures that the user it able to set the REG_PORT using an environment variable and then use make dev after which consumes the REG_PORT env var to create the kind-registry exposed on the aforementioned port.

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[Copilot]

Pull Request Overview

This PR updates the development documentation to allow users to specify a custom Docker registry port via the REG_PORT environment variable.

• Added a section detailing how to configure the registry port.
• Provided a code snippet showing how to set REG_PORT and run "make dev".

Files not reviewed (1)

• hack/dev/kind/install.sh: Language not supported

[waveywaves]

cc @chmouel @zakisk

[chmouel]

sounds good but we probably going to move everything to https://github.com/chmouel/startpaac soon :)

[waveywaves]

@chmouel I created my own script for setting up PAC, wanted to test with github ANND have everything run on kind. Also, allowed me to replace the instance of pac running with ko apply -f config with KO_DOCKER_REPO=localhost:5001

[chmouel]

@waveywaves startpaac does that too (on local) ;) but no worries if you want to use your own...