How to install plugins with specific branch
When I try to install [coc.nvim](https://github.com/neoclide/coc.nvim),
it required specific branch, for example
```vim
" Use release branch (recommend)
Plug 'neoclide/coc.nvim', {'branch': 'release'}

" Or build from source code by using yarn: https://yarnpkg.com
Plug 'neoclide/coc.nvim', {'branch': 'master', 'do': 'yarn install --frozen-lockfile'}
```
However I don't know how to set in `[[custom_plugins]]`  Configuration.
What should I do next? Thank you for your help!