Feature Request: Optional neovim/neovim-release support

[Davidyz]

Is your feature request related to a problem? Please describe.
The official neovim builds are built against a fairly recent glibc, while some servers (mostly compute servers) have very old environments where the latest stable neovim wouldn't run.

Describe the solution you'd like
Optional (opt-in via an interactive dialogue and/or configuration) support for https://github.com/neovim/neovim-releases which builds against glibc 2.17.

Describe alternatives you've considered
Manually download and install from https://github.com/neovim/neovim-releases, which is a lot more troublesome.

Additional context
N/A