be copyable to use

hi @CHH. Thanks for phpenv, and php-build.
just tiny fix for more copyable to use.
Thanks.

### before: 

```
Success.

Now add /home/ec2-user/.phpenv/bin to your $PATH, add 'eval "$(phpenv init -)"' at the end of your ~/.bashrc and restart your shell to use phpenv.

```

### after: 

```
Success.

export PATH="/Users/banyan/.phpenv/bin:$PATH"
eval "$(phpenv init -)"

Add above line at the end of your ~/.bashrc and restart your shell to use phpenv.

```