Recommend Docker as installation method (w/ Bash alias)

[maresb]

No description provided.

[maresb]

Partially resolves #242

(It remains to delete or replace the Ubuntu installation instructions.)

[wagoodman]

Thanks for the suggestion, however, I'd prefer not to recommend the docker approach over the other packages. Though this week it was certainly true that the docker method was the preferred approach (while 0.9.0 was broken)! However, this is no longer the case since 0.9.1 has removed the offending dependencies.

Sorry for the installation frustration this week! I'll be adding more pipeline steps to specifically test package installation to ensure this doesn't happen again.

[eine]

@wagoodman, while I do agree with not suggesting docker over other packages for golang projects in general, I beg to partially differ for this specific project. dive is currently almost dependent on docker. It is possible to use it without access to a docker daemon, but the vast majority of users will need the daemon; until podman is multiplaform, at least. Therefore, provided that docker is already installed on the system, it seems natural to avoid installing a binary which is not properly supported (#242 (comment)) in a package manager.

This is not to say that we should suggest docker first. But I think, that this PR is a good excuse to add a paragraph in the beginning of https://github.com/wagoodman/dive#installation, so that users can read a brief discussion to decide how to install dive. Note that, regarding #224, there might be UX differences in the future.