Touch up docs for shell completion scripts

etc/README.md

@@ -6,7 +6,7 @@ If you're using Homebrew, just run `brew install hub` and you should be all set
 
 ## bash
 
-Open your `.bashrc` file if you're on Linux, or your `.bash_profile` if you're on OS X and add:
+Open your `.bashrc` file if you're on Linux, or your `.bash_profile` if you're on macOS and add:
 
 ```sh
 if [ -f /path/to/hub.bash_completion ]; then
@@ -16,17 +16,12 @@ fi
 
 ## zsh
 
-Create a new folder for completions:
+Copy the file `etc/hub.zsh_completion` from the location where you downloaded
+`hub` to the folder `~/.zsh/completions/` and rename it to `_hub`:
 
 ```sh
 mkdir -p ~/.zsh/completions
-```
-
-Copy the file `/etc/hub.zsh_completion` from the location where you downloaded `hub` to the folder `~/.zsh/completions/` and rename it to `_hub`:
-
-```sh
-cp /path/to/etc/hub.zsh_completion ~/.zsh/completions/ \
-    mv ~/.zsh/completions/hub.zsh_completion ~/.zsh/completions/_hub
+cp etc/hub.zsh_completion ~/.zsh/completions/_hub
 ```
 
 Then add the following lines to your `.zshrc` file:
@@ -38,10 +33,10 @@ autoload -U compinit && compinit
 
 ## fish
 
-Copy the file `/etc/hub.fish_completion` from the location where you downloaded
+Copy the file `etc/hub.fish_completion` from the location where you downloaded
 `hub` to the folder `~/.config/fish/completions/` and rename it to `hub.fish`:
 
 ```sh
 mkdir -p ~/.config/fish/completions
-cp /path/to/etc/hub.fish_completion ~/.config/fish/completions/hub.fish
+cp etc/hub.fish_completion ~/.config/fish/completions/hub.fish
 ```