Mention breaking change#1623

CharlesTaylor7 wants to merge 1 commit intonushell:release-notes-0.100.0nushell/nushell.github.io:release-notes-0.100.0from

CharlesTaylor7:charles/v0.100.0CharlesTaylor7/nushell.github.io:charles/v0.100.0Copy head branch name to clipboard