updated README

README.md

@@ -7,12 +7,16 @@ tools that do one thing well.
 This project was forked from [rbenv](https://github.com/sstephenson/rbenv) and.
 [ruby-build](https://github.com/sstephenson/ruby-build) and modified for Python.
 
+<img src="http://gyazo.com/13719131550e2d53269ad38c8a0a1815.png?1346413840" width="841" height="448">
+
 ### pyenv _does…_
 
 * Let you **change the global Python version** on a per-user basis.
 * Provide support for **per-project Python versions**.
 * Allow you to **override the Python version** with an environment
   variable.
+* Search commands from multiple versions of Python at a time.
+  This may be helpful to test across Python versions with [tox](http://pypi.python.org/pypi/tox).
 
 ## Table of Contents
 
@@ -20,7 +24,16 @@ This project was forked from [rbenv](https://github.com/sstephenson/rbenv) and.
    * [2 Installation](#section_2)
       * [2.1 Basic GitHub Checkout](#section_2.1)
          * [2.1.1 Upgrading](#section_2.1.1)
+      * [2.2 Neckbeard Configuration](#section_2.3)
    * [3 Usage](#section_3)
+      * [3.1 pyenv global](#section_3.1)
+      * [3.2 pyenv local](#section_3.2)
+      * [3.3 pyenv shell](#section_3.3)
+      * [3.4 pyenv versions](#section_3.4)
+      * [3.5 pyenv version](#section_3.5)
+      * [3.6 pyenv rehash](#section_3.6)
+      * [3.7 pyenv which](#section_3.7)
+      * [3.8 pyenv whence](#section_3.8)
    * [4 Development](#section_4)
       * [4.1 Version History](#section_4.1)
       * [4.2 License](#section_4.2)
@@ -103,13 +116,155 @@ tag:
     $ git fetch
     $ git tag
     v0.1.0
-    v0.1.1
+    $ git checkout v0.1.0
-    v0.1.2
+
-    v0.2.0
+### <a name="section_2.2"></a> 2.2 Neckbeard Configuration
-    $ git checkout v0.2.0
+
+Skip this section unless you must know what every line in your shell
+profile is doing.
+
+`pyenv init` is the only command that crosses the line of loading
+extra commands into your shell. Coming from rvm, some of you might be
+opposed to this idea. Here's what `pyenv init` actually does:
+
+1. Sets up your shims path. This is the only requirement for pyenv to
+   function properly. You can do this by hand by prepending
+   `~/.pyenv/shims` to your `$PATH`.
+
+2. Installs autocompletion. This is entirely optional but pretty
+   useful. Sourcing `~/.pyenv/completions/pyenv.bash` will set that
+   up. There is also a `~/.pyenv/completions/pyenv.zsh` for Zsh
+   users.
+
+3. Rehashes shims. From time to time you'll need to rebuild your
+   shim files. Doing this on init makes sure everything is up to
+   date. You can always run `pyenv rehash` manually.
+
+4. Installs the sh dispatcher. This bit is also optional, but allows
+   pyenv and plugins to change variables in your current shell, making
+   commands like `pyenv shell` possible. The sh dispatcher doesn't do
+   anything crazy like override `cd` or hack your shell prompt, but if
+   for some reason you need `pyenv` to be a real script rather than a
+   shell function, you can safely skip it.
+
+Run `pyenv init -` for yourself to see exactly what happens under the
+hood.
 
 ## <a name="section_3"></a> 3 Usage
 
+Like `git`, the `pyenv` command delegates to subcommands based on its
+first argument. The most common subcommands are:
+
+### <a name="section_3.1"></a> 3.1 pyenv global
+
+Sets the global version of Python to be used in all shells by writing
+the version name to the `~/.pyenv/version` file. This version can be
+overridden by a per-project `.pyenv-version` file, or by setting the
+`PYENV_VERSION` environment variable.
+
+    $ pyenv global 2.7.3
+
+The special version name `system` tells pyenv to use the system Python
+(detected by searching your `$PATH`).
+
+When run without a version number, `pyenv global` reports the
+currently configured global version.
+
+_pyenv extension_
+
+You can specify multiple versions for global Python. Commands within
+these versions are searched by specified order.
+
+    $ pyenv global 2.7.3 3.2.3
+    $ pyenv global
+    2.7.3
+    3.2.3
+
+### <a name="section_3.2"></a> 3.2 pyenv local
+
+Sets a local per-project Python version by writing the version name to
+an `.pyenv-version` file in the current directory. This version
+overrides the global, and can be overridden itself by setting the
+`PYENV_VERSION` environment variable or with the `pyenv shell`
+command.
+
+    $ pyenv local rbx-1.2.4
+
+When run without a version number, `pyenv local` reports the currently
+configured local version. You can also unset the local version:
+
+    $ pyenv local --unset
+
+_pyenv extension_
+
+You can specify multiple versions for local Python.
+
+### <a name="section_3.3"></a> 3.3 pyenv shell
+
+Sets a shell-specific Python version by setting the `PYENV_VERSION`
+environment variable in your shell. This version overrides both
+project-specific versions and the global version.
+
+    $ pyenv shell pypy-1.9
+
+When run without a version number, `pyenv shell` reports the current
+value of `PYENV_VERSION`. You can also unset the shell version:
+
+    $ pyenv shell --unset
+
+Note that you'll need pyenv's shell integration enabled (step 3 of
+the installation instructions) in order to use this command. If you
+prefer not to use shell integration, you may simply set the
+`PYENV_VERSION` variable yourself:
+
+    $ export PYENV_VERSION=pypy-1.9
+
+### <a name="section_3.4"></a> 3.4 pyenv versions
+
+Lists all Python versions known to pyenv, and shows an asterisk next to
+the currently active version.
+
+    $ pyenv versions
+      2.5.6
+      2.6.8
+    * 2.7.3 (set by /home/yyuu/.pyenv/version)
+      3.2.3
+      jython-2.5.3
+      pypy-1.9
+
+### <a name="section_3.5"></a> 3.5 pyenv version
+
+Displays the currently active Python version, along with information on
+how it was set.
+
+    $ pyenv version
+    2.7.3 (set by /home/yyuu/.pyenv/version)
+
+### <a name="section_3.6"></a> 3.6 pyenv rehash
+
+Installs shims for all Python binaries known to pyenv (i.e.,
+`~/.pyenv/versions/*/bin/*`). Run this command after you install a new
+version of Python, or install a gem that provides binaries.
+
+    $ pyenv rehash
+
+### <a name="section_3.7"></a> 3.7 pyenv which
+
+Displays the full path to the binary that pyenv will execute when you
+run the given command.
+
+    $ pyenv which python3.2
+    /Users/sam/.pyenv/versions/3.2.3/bin/python3.2
+
+### <a name="section_3.8"></a> 3.8 pyenv whence
+
+Lists all Python versions with the given command installed.
+
+    $ pyenv whence 2to3
+    2.6.8
+    2.7.3
+    3.2.3
+
 ## <a name="section_4"></a> 4 Development
 
 The pyenv source code is [hosted on