prevent merge when there's multiple commits in a PR

github.com.js

var num_commits = parseInt($('#commits_tab_counter').text());
var button = $("div.merge-message > button");
if (num_commits > 1) {
    console.log("disabling");
    button.attr('disabled','disabled');
    button.text("Squash those commits!");
    div = $("div.merge-message");
    div.append("<button class='btn btn-primary' id='enable_merge' style='float:right;' type='button'>Override</button>");
    enable_button = $('button#enable_merge');
    
    enable_button.on('click', function() {
        console.log("re-enabling button");
        button.removeAttr('disabled');
        button.text("Merge without squash");
    });
}