This commit adds the subcommands `get-config` and `set-config` to Serve,
which can be used to read the current Tailscale Services configuration
in a standard syntax and provide a configuration to declaratively apply
with that same syntax.
Both commands must be provided with either `--service=svc:service` for
one service, or `--all` for all services. When writing a config,
`--set-config --all` will overwrite all existing Services configuration,
and `--set-config --service=svc:service` will overwrite all
configuration for that particular Service. Incremental changes are not
supported.
Fixestailscale/corp#30983.
cmd/tailscale/cli: hide serve "get-config"/"set-config" commands for now
tailscale/corp#33152 tracks unhiding them when docs exist.
Signed-off-by: Naman Sood <mail@nsood.in>
Naman Sood