HPCC-11780 DOCS:Update ECL Playground for ECL Watch 5.0

Fix HPCC-11780 DOCS:Update ECL Playground for ECL Watch 5.0
Update images and  language to
descibe the ECL Playground in ECL Watch 5.0

Signed-off-by: g-pan <greg.panagiotatos@lexisnexis.com>