docs(sync-files): add installation instructions

[xmfcx]

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[xmfcx]

• ci: port workflows from autoware.universe autoware_tools#1

@mitsudome-r it seems you've missed it while setting this repository up.

• Because the following job is skipped.
  • https://github.com/autowarefoundation/autoware_tools/actions/runs/8041762108/job/21961464644

I have figured it out while I was setting up the CI for:

• ci: initialize autoware_internal_msgs#2
• ci(sync-files): add workflow autoware_internal_msgs#3
  • https://github.com/autowarefoundation/autoware_internal_msgs/actions/runs/8050831835

[xmfcx]

@mitsudome-r I will fix the autoware_tools repository setup for this action using these instructions.

Done, now it works:

• https://github.com/autowarefoundation/autoware_tools/actions/runs/8052065731

[xmfcx]

@mitsudome-r you took too long to review, I'm merging it since it's just docs.