Added link to Bazelisk in installation doc for Ubuntu
Added link to Bazelisk in installation doc for Ubuntu

Closes #11988.

PiperOrigin-RevId: 327819311

meteorcloudy/bazel,safarmer/bazel,meteorcloudy/bazel,davidzchen/bazel,perezd/bazel,werkt/bazel,bazelbuild/bazel,werkt/bazel,perezd/bazel,twitter-forks/bazel,werkt/bazel,werkt/bazel,twitter-forks/bazel,cushon/bazel,davidzchen/bazel,werkt/bazel,ButterflyNetwork/bazel,ButterflyNetwork/bazel,perezd/bazel,davidzchen/bazel,meteorcloudy/bazel,katre/bazel,bazelbuild/bazel,perezd/bazel,ButterflyNetwork/bazel,katre/bazel,ButterflyNetwork/bazel,twitter-forks/bazel,safarmer/bazel,davidzchen/bazel,safarmer/bazel,katre/bazel,twitter-forks/bazel,katre/bazel,meteorcloudy/bazel,cushon/bazel,perezd/bazel,bazelbuild/bazel,cushon/bazel,twitter-forks/bazel,davidzchen/bazel,cushon/bazel,bazelbuild/bazel,cushon/bazel,twitter-forks/bazel,safarmer/bazel,bazelbuild/bazel,katre/bazel,meteorcloudy/bazel,bazelbuild/bazel,davidzchen/bazel,meteorcloudy/bazel,safarmer/bazel,safarmer/bazel,cushon/bazel,katre/bazel,ButterflyNetwork/bazel,werkt/bazel,ButterflyNetwork/bazel,perezd/bazel,perezd/bazel,davidzchen/bazel,twitter-forks/bazel,meteorcloudy/bazel