build: support pkg managers installation (#87)

closes #71, #84, #86
- AUR
- Homebrew
- Nix
- Debian (.deb)
- RPM (.rpm)
- Aqua
- ASDF

This is my first time doing this, so there might be mistakes. If you
can't download it through any pkg manager, please leave a comment or
open an issue

---------

Co-authored-by: use-the-fork <23747916+use-the-fork@users.noreply.github.com>

packaging/asdf/bin/install

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+[ -n "$ASDF_INSTALL_PATH" ] || { echo "ASDF_INSTALL_PATH is required" >&2; exit 1; }
+[ -n "$ASDF_DOWNLOAD_PATH" ] || { echo "ASDF_DOWNLOAD_PATH is required" >&2; exit 1; }
+
+mkdir -p "$ASDF_INSTALL_PATH/bin"
+cp "$ASDF_DOWNLOAD_PATH/iris" "$ASDF_INSTALL_PATH/bin/iris"
+chmod +x "$ASDF_INSTALL_PATH/bin/iris"