Documentation for list command not on list url

[sth]

The documentation for list is still found on https://yarnpkg.com/en/docs/cli/ls, not https://yarnpkg.com/en/docs/cli/list . It should be renamed and a redirect from ls to list should de added.

Yarn itself already points to https://yarnpkg.com/en/docs/cli/list in its help message:

$ yarn ls 
yarn ls v0.19.1
error Did you mean `yarn list`?
info Visit https://yarnpkg.com/en/docs/cli/list for documentation about this command.

Currently this URL shows a 404.

[grant]

Fixes part of the issue: #356

[Haroenv]

closed of #377