Support ssh-key for k3sup plan

Fixes: #436

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Update to message in get.sh

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Add --no-extra flag to join command

It was found that when joining servers to a cluster any additional servers
would not honour the `--no-extras` flag used with the install command.

It is necessary, therefore, for the flag to be added to `join` and only
be applied in situations where `--server` has been provided.

Signed-off-by: Richard Gee <[email protected]>

Bump golang.org/x/crypto from 0.13.0 to 0.17.0

Bumps [golang.org/x/crypto](https://github.com/golang/crypto) from 0.13.0 to 0.17.0.
- [Commits](golang/crypto@v0.13.0...v0.17.0)

---
updated-dependencies:
- dependency-name: golang.org/x/crypto
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Add --server-k3s-extra-args for disabling traefik etc

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Add notes to README for k3sup plan

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Update vendor

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Ignore gofmt errors from vendor folder

This started failing with Go 1.20, but I haven't been able
to find out why yet, despite vendor being excluded from the
list of packages/files to test.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Replace sponsorship note with actuated info

Folks do not sponsor me, it's sad, and unfortunate, but I
know they love and use k3sup extensively.

Perhaps they'll also like actuated.

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Add --tls-san for join command for servers

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>