docs: Add more information on installing via a package manager

[exdx]

The statement "Get the plugin via your favorite plugin manager" in the README likely makes a lot of sense to advanced neovim users. But if the user is newer to neovim, and doesn't necessarily have a plugin manager, it's not very helpful. It would be great to provide some additional context:

• What package managers are available (and which one is preferred)?
• What's the name of the package to install? Is it nvim-ide?
• Are there any additional caveats? For example, does installing on windows work OOTB?

[ldelossa]

Good call.

I don't think i'd like to list all the package managers in the neovim ecosystem. And I only really use plug, so maybe I'll put an example of that in the Readme, and users of other plugin managers can add their own examples.

[exdx]

Yes, I think that's a good way to go

[ldelossa]

I think Peppo would approve.

[mrjones2014]

I think the majority of users these days use packer.nvim so its probably worth listing both vim-plug and packer.nvim instructions. Those are the two most popular by far.

[exdx]

I can take a look at this. I'm familiar with both those projects, but barely lol. Will try to have something up over the weekend.

[exdx]

Addressed in the linked PR.