Add README for vundle plugin (#7245)

plugins/vundle/README.md

+# Vundle plugin
+
+This plugin adds functions to control [vundle](https://github.com/VundleVim/Vundle.vim) plug-in manager for vim.
+
+To use it, add `vundle` to the plugins array in your zshrc file:
+
+```zsh
+plugins=(... vundle)
+```
+
+## Functions
+
+| Function      | Usage           | Description                                                                |
+|---------------|-----------------|----------------------------------------------------------------------------|
+| vundle-init   | `vundle-init`   | Install vundle by cloning git repository into ~/.vim folder                |
+| vundle        | `vundle`        | Install plugins set in .vimrc (equals `:PluginInstall`)                    |
+| vundle-update | `vundle-update` | Update plugins set in .vimrc (equals `:PluginInstall!`)                    |
+| vundle-clean  | `vundle-clean`  | Delete plugins that have been removed from .vimrc (equals `:PluginClean!`) |
+