Updates root readme weight to fix display order on website
Updates root readme weight to fix display order on website

This updates the weight of root readme which seems to be deciding
factor for order in which components appears on website.

Ref. https://github.com/tektoncd/website/pull/306#discussion_r736517449

Signed-off-by: Shivam Mukhade <330299940dbe3b9a5e12a3de6ca29752465435c4@redhat.com>

tektoncd/operator,tektoncd/operator,tektoncd/operator