feat(zen-mode-nvim): add integration with vim-matchup if enabled

[Subjective]

This fixes an assortment of weird visual bugs when using vim-matchup in zen-mode:
Before:

After:

[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]

@Subjective Could you add some info about the integrations in the readme? Else, it looks good to me :)

[Subjective]

@Uzaaft done :)