Add linting to root dashboard folder

[richard-cox]

• in the future we should hopefully get his for free with shell
• depends on Use new rancher shell by default (instead of yarn link'ing it in) #257

[torchiaf]

LGTM.
I resolved some conflicts with main branch and pushed some minor fixes.
The lint task works locally.

[richard-cox]

Thanks. Note, in markdown renderers will automatically change those 1s to sequential numbers - https://stackoverflow.com/a/12145270/2569500