feat(indent): add indent-rainbowline

[fuchami]

📑 Description

Add rainbow indents plugin.

https://github.com/TheGLander/indent-rainbowline.nvim

ℹ Additional Information

[github-actions]

Review Checklist

Does this PR follow the [Contribution Guidelines](development guidelines)? Following is a partial checklist:

Proper conventional commit scoping:

• If you are adding a new plugin, the scope would be the name of the category it is being added into. ex. feat(utility): added noice.nvim plugin

• If you are modifying a pre-existing plugin or pack, the scope would be the name of the plugin folder. ex. fix(noice-nvim): fix LSP handler error

• Pull request title has the appropriate conventional commit type and scope where the scope is the name of the pre-existing directory in the project as described above

• README is properly formatted and uses fenced in links with <url> unless they are inside a [title](url)

• Proper usage of opts table rather than setting things up with the config function.

[Uzaaft]

#634

[Uzaaft]

Feel free to re-open this for v4 to Get it merged ASAP

[fuchami]

I plan to add this feature after v4 is released. thank you.

[Uzaaft]

R? @AstroNvim/astrocommunity-maintainers

[mehalter]

Added a suggestion that would allow users to use the opts table for indent-rainbowline to configure the make_opts call

[Uzaaft]

LGTM now. :) Any last words @mehalter

[mehalter]

LGTM