Add documentation

README.md

@@ -116,7 +116,7 @@ The segments that are currently available are:
    * `go_version` - Show the current GO version.
* **Javascript / Node.js Segments:**
    * `node_version` - Show the version number of the installed Node.js.
    * `nodeenv` - [nodeenv](https://github.com/ekalinin/nodeenv) prompt for displaying node version and environment name.
    * [`nodeenv`](#nodeenv) - [nodeenv](https://github.com/ekalinin/nodeenv) prompt for displaying node version and environment name.
    * `nvm` - Show the version of Node that is currently active, if it differs from the version used by NVM
* **PHP Segments:**
    * `php_version` - Show the current PHP version.
@@ -557,6 +557,12 @@ prompt itself.

This only works on the left side.  On the right side it does nothing.

##### nodeenv

Shows the currently used [nodeenv](https://github.com/ekalinin/nodeenv). To avoid
Nodeenvs activate command from interfering with Powerlevel9k, you should set
`NODE_VIRTUAL_ENV_DISABLE_PROMPT=1` in your `~/.zshrc`.

##### rbenv

This segment shows the version of Ruby being used when using `rbenv` to change your current Ruby stack.