LRDOCS-868: Update Themes for Liferay IDE 2.0
LRDOCS-868: Update Layout template section for IDE 2.0
LRDOCS-863: Correct snapshots to display 6.1 SDK and runtime
LRDOCS-863: Update Themes chapter for IDE 2.0
LRDOCS-879: Update Ext section for Liferay IDE 2.0
LRDOCS-864: Edit Maven chapter nesting