SimpleDesk

In Subs-SimpleDeskPackages.php missing variable
$scripturl
$txt
$packages

find
function shd_packages_sort_id(&$sort_id, &$packages)
{
    global $context;
replaces with
function shd_packages_sort_id(&$sort_id, &$packages)
{
    global $context, $packages;

find
function shd_package_download()
{
    global $context;
replaces with
function shd_package_download()
{
    global $context, $scripturl, $txt;

find
function shd_package_upload()
{
    global $context;
replace with
function shd_package_upload()
{
    global $context, $scripturl, $txt;

All done.  I submitted this for you: https://www.simpledesk.net/community/index.php?topic=2184

Hopefully that helps give a picture of how to work with Git and GitHub.