Update standalone binary installation docs for Ubuntu/debian that refer to 'bintray'

[munim-db]

What is incorrect, confusing or missing:

The current documentation here and here, refer to the repository hosted in bintray: https://dl.bintray.com/tetrate/getenvoy-deb which is being sunset on May 1st 2021 https://jfrog.com/blog/into-the-sunset-bintray-jcenter-gocenter-and-chartcenter/

Suggested fix:
This commit seems to suggest that the binaries have been migrated to clousmith: tetratelabs/func-e@18ec725

The installation docs for Ubuntu/debian should be updated to reflect the same.