Document PREFIX

Author: devm33

README.md

@@ -57,6 +57,9 @@ Or
 wget -qO- https://gh.io/copilot-install | bash
 ```
 
+Set `PREFIX` to install to `$PREFIX/bin/` directory. Defaults to `/usr/local`
+when run as root or `$HOME/.local` when run as a non-root user.
+
 #### macOS
 
 Install with [Homebrew](https://formulae.brew.sh/cask/copilot-cli):

install.sh

@@ -4,6 +4,8 @@ set -e
 # GitHub Copilot CLI Installation Script
 # Usage: curl -fsSL https://gh.io/copilot-install | bash
 #    or: wget -qO- https://gh.io/copilot-install | bash
+# Set PREFIX to install to $PREFIX/bin/ directory (default: /usr/local for root,
+# $HOME/.local for non-root)
 
 echo "Installing GitHub Copilot CLI..."