Updated README with GraphX information
Updated README with GraphX information

ldbc/ldbc_graphalytics,tudelft-atlarge/graphalytics,tudelft-atlarge/graphalytics,ldbc/ldbc_graphalytics,tudelft-atlarge/graphalytics,tudelft-atlarge/graphalytics,ldbc/ldbc_graphalytics,tudelft-atlarge/graphalytics,ldbc/ldbc_graphalytics,ldbc/ldbc_graphalytics