helm: Update documentation links to point to stable
helm: Update documentation links to point to stable

These settings should point to the currently supported stable version of
the docs rather than the development version, point to stable instead of
latest.

Signed-off-by: Joe Stringer <16a9a54ddf4259952e3c118c763138e83693d7fd@cilium.io>

tklauser/cilium,michi-covalent/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium,cilium/cilium,michi-covalent/cilium,tgraf/cilium,tklauser/cilium,tgraf/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,tgraf/cilium,tklauser/cilium,tgraf/cilium,tklauser/cilium,cilium/cilium,tgraf/cilium