Feat: Support macOS and Windows, migrate JavaScript to TypeScript (#32)

- Support macOS and Windows (Close #24 )
- Refactoring
  - Error handling
  - TypeScript
- Prettier (Close #29 )
- GHA: Add upload-artifact step for test coverage
- deps: Install husky

src/get-url.ts

@@ -0,0 +1,31 @@
+export default function getURL(
+  os: string,
+  extended: string,
+  version: string
+): string {
+  const extendedStr = (extended: string) => {
+    if (extended === 'true') {
+      return 'extended_';
+    } else {
+      return '';
+      // } else {
+      //   throw new Error(`Invalid input (extended): ${extended}`);
+    }
+  };
+
+  const ext = (os: string) => {
+    if (os === 'Windows') {
+      return 'zip';
+    } else {
+      return 'tar.gz';
+    }
+  };
+
+  const hugoName: string = `hugo_${extendedStr(
+    extended
+  )}${version}_${os}-64bit`;
+  const baseURL: string = 'https://github.com/gohugoio/hugo/releases/download';
+  const url: string = `${baseURL}/v${version}/${hugoName}.${ext(os)}`;
+
+  return url;
+}