fix(tailwindcss): add mjs support for tailwind root dir detection

[nemmtor]

📑 Description

After updating to new version which included this PR I noticed my tailwind intellisense stopped working and :LspInfo: shows that rootDir was not found.

I spotted that mentioned above PR didn't include .mjs extension which I use in my projects for tailwind config files.

[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.