zsh_reload: add README

plugins/zsh_reload/README.md

+# zsh_reload plugin
+
+The zsh_reload plugin defines a function to reload the zsh session with
+just a few keystrokes.
+
+To use it, add `zsh_reload` to the plugins array in your zshrc file:
+
+```zsh
+plugins=(... zsh_reload)
+```
+
+## Usage
+
+To reload the zsh session, just run `src`:
+
+```zsh
+$ vim ~/.zshrc  # enabled a plugin
+$ src
+re-compiling /home/user/.zshrc.zwc: succeeded
+re-compiling /home/user/.oh-my-zsh/cache/zcomp-host.zwc: succeeded
+
+# you now have a fresh zsh session. happy hacking!
+```