linux installation sctipt

[ndeloof]

Added installation script for Linuxes.
Based on @ulyssessouza's previous script, with minor changes:

• doesn't install Compose V2 (which is managed by [master] add docker-compose-plugin package (deb, rpm) docker-ce-packaging#553)
• uses bin/sh, not bash, so can be used on Alpine
• uses mktemp to create temporary file for download

[ndeloof]

tested within an alpine container with fake /usr/bin/docker and /usr/bin/docker-compose:

/work # ./install_on_linux.sh 
Downloading compose v1->v2 switch into /tmp/tmp.CdEldo...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100     9  100     9    0     0     42      0 --:--:-- --:--:-- --:--:--    42
Switching Docker Compose binary
Compose v1->v2 installed
Docker Compose V2 enabled
To switch back to compose v1, you can run:
$ docker-compose disable-v2

[mat007]

Looks good, some nits 😀

[mat007]

Is this not the final URL now?

[lorenrh]

LGTM!