Avoid suggesting that people use .zshenv.local

`.zshenv` is executed for all zsh programs, even those run from
executables and not as an interactive shell, and furthermore due to
OS X's use of `path_helper` in `/etc/zprofile` which runs after that,
it's not a good place to configure additional PATH entries.

From zsh(1) man page:

> As /etc/zshenv is run for all instances of zsh, it is important that
> it be kept as small as possible.

So `.zshenv` is generally considered advanced usage and is not
recommended that people drop their casual login shell config in here.
Because of people's historical misuse of `.zshenv`, stop documenting it
in the README and suggest that people do their PATH and other
configuration in `.zshrc`.

README.md

@@ -59,7 +59,6 @@ Put your customizations in dotfiles appended with `.local`:
 * `~/.tmux.conf.local`
 * `~/.vimrc.local`
 * `~/.vimrc.bundles.local`
-* `~/.zshenv.local`
 * `~/.zshrc.local`
 * `~/.zsh/configs/*`
 
@@ -85,20 +84,15 @@ Your `~/.vimrc.local` might look like this:
     highlight NonText guibg=#060606
     highlight Folded  guibg=#0A0A0A guifg=#9090D0
 
-Your `~/.zshenv.local` might look like this:
-
-    # load pyenv if available
-    if command -v pyenv &>/dev/null ; then
-      eval "$(pyenv init -)"
-    fi
-
 To extend your `git` hooks, create executable scripts in
 `~/.git_template.local/hooks/*` files.
 
 Your `~/.zshrc.local` might look like this:
 
-    # recommended by brew doctor
-    export PATH="/usr/local/bin:/usr/local/sbin:$PATH"
+    # load pyenv if available
+    if which pyenv &>/dev/null ; then
+      eval "$(pyenv init -)"
+    fi
 
 Your `~/.vimrc.bundles.local` might look like this: