[DOCUMENTATION] Update README Contents With Warnings About Ciphers/MACs/Kex Settings

[ferricoxide]

From Issue #703 (originally submitted by @aaronlippold), some methods used for invoking spel (and related projects' contents) may result in SSH configurations that cause clients to be unable to connect without updating their configs to be compatible with the remote's SSH-related security settings (see: issue-comment 2351911481)

It may be helpful to add a note to this project's READMEs that the client/server config-deltas may cause issues with some workflows and/or clients.