fix: modify install script for alpine

Author: jsjoeio

install.sh

@@ -58,7 +58,7 @@ Usage:
   - If Homebrew is not installed it will install the latest standalone release
     into ~/.local
 
-- For FreeBSD, it will install the npm package with yarn or npm.
+- For FreeBSD or Alpine, it will install the npm package with yarn or npm.
 
 - If ran on an architecture with no releases, it will install the
   npm package with yarn or npm.
@@ -238,6 +238,17 @@ main() {
     return
   fi
 
+  if [ "$OS" = "linux" ] && [ "$(distro)" = "alpine" ]; then
+    if [ "$METHOD" = standalone ]; then
+      echoerr "No precompiled releases available for alpine."
+      echoerr 'Please rerun without the "--method standalone" flag to install from npm.'
+      exit 1
+    fi
+    echoh "No precompiled releases available for alpine."
+    install_npm
+    return
+  fi
+
   CACHE_DIR="$(echo_cache_dir)"
 
   if [ "$METHOD" = standalone ]; then
@@ -473,6 +484,11 @@ distro() {
     )
     return
   fi
+
+  if [ -f /etc/alpine-release ]; then
+    echo "alpine"
+    return
+  fi
 }
 
 # os_name prints a pretty human readable name for the OS/Distro.