Missing documentation for the `--ignore-workspace` option

[laesse]

I did not find a reference to the --ignore-worksapce option on the docs page. This option skips the check for a pnpm-workspace.yaml in a parent directory, this is very useful if you're migrating an existing monorepo, incrementally into a pnpm workspace. The only place outside the code where I found a reference was this GitHub discussion thread and the changelog entry for version 6.25.0

[MoazAlkharfan]

Hello! Every line missing from the documentation accumulates wasted time for multiple people using pnpm Please keep the documentation updated <3