Update tanka installation docs to refer to tanka section about `jb` (#4208)
Update tanka installation docs to refer to tanka section about `jb` (#4208)

installation instead of providing a cli command that may not work.

Signed-off-by: Callum Styan <106b387c595dcc1a235f6eff749ea0675b25b42d@gmail.com>
grafana/loki,grafana/loki,grafana/loki,grafana/loki,grafana/loki,grafana/loki