temurin: add support for Alpine Linux

Author: gdams

Diff for: src/distributions/temurin/installer.ts

@@ -170,11 +170,16 @@ export class TemurinDistribution extends JavaBase {
     // Adoptium has own platform names so need to map them
     switch (process.platform) {
       case 'darwin':
-        return 'mac';
+      return 'mac';
       case 'win32':
-        return 'windows';
+      return 'windows';
+      case 'linux':
+      if (fs.existsSync('/etc/alpine-release')) {
+        return 'alpine-linux';
+      }
+      return 'linux';
       default:
-        return process.platform;
+      return process.platform;
     }
   }
 }