refactor(repo): create repo package

- Refactor `installer.clone` into new `repo.Clone` package and method.

- Refactor `sheets.isGitDir` into `repo.GitDir`.

Both of these changes read better, and will facilitate cleaner
architecture when `--update` is implemented.

internal/installer/clone.go

@@ -1,25 +0,0 @@
-package installer
-
-import (
-	"fmt"
-	"os"
-
-	"github.com/go-git/go-git/v5"
-)
-
-// clone clones the community cheatsheets
-func clone(path string) error {
-
-	// clone the community cheatsheets
-	_, err := git.PlainClone(path, false, &git.CloneOptions{
-		URL:      "https://github.com/cheat/cheatsheets.git",
-		Depth:    1,
-		Progress: os.Stdout,
-	})
-
-	if err != nil {
-		return fmt.Errorf("failed to clone cheatsheets: %v", err)
-	}
-
-	return nil
-}

internal/installer/run.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/cheat/cheat/internal/config"
+	"github.com/cheat/cheat/internal/repo"
 )
 
 // Run runs the installer
@@ -45,7 +46,7 @@ func Run(configs string, confpath string) error {
 	if yes {
 		// clone the community cheatsheets
 		fmt.Printf("Cloning community cheatsheets to %s.\n", community)
-		if err := clone(community); err != nil {
+		if err := repo.Clone(community); err != nil {
 			return fmt.Errorf("failed to clone cheatsheets: %v", err)
 		}