rewrite gh repo create (cli#4578)

Co-authored-by: Parth Patel <ppatil91099@gmail.com>

Author: meiji163

git/git.go

@@ -366,6 +366,16 @@ func ToplevelDir() (string, error) {
 
 }
 
+// ToplevelDirFromPath returns the top-level given path of the current repository
+func GetDirFromPath(p string) (string, error) {
+	showCmd, err := GitCommand("-C", p, "rev-parse", "--git-dir")
+	if err != nil {
+		return "", err
+	}
+	output, err := run.PrepareCmd(showCmd).Output()
+	return firstLine(output), err
+}
+
 func PathFromRepoRoot() string {
 	showCmd, err := GitCommand("rev-parse", "--show-prefix")
 	if err != nil {