Ссылки:

Add snippet.css with this content:

/* Hiding the "catalog" folder */
div[data-path='catalog'],
div[data-path='catalog'] + div.nav-folder-children
{
display: none;
}
/* Hiding the "blogs" folder */
div[data-path='blogs'],
div[data-path='blogs'] + div.nav-folder-children
{
display: none;
}
/* Hiding the "index.md" file */
div[data-path='index.md'],
div[data-path='index.md'] + div.nav-folder-children
{
display: none;
}