HPCC-10911 DOCS:start up logging

HPCC-10911 DOCS:start up logging
Document the new hpcc-init log which
logs start up init activity

Signed-off-by: g-pan <greg.panagiotatos@lexisnexis.com>
Merge pull request #5513 from g-pan/H10911-initlog

HPCC-10911 DOCS:start up logging

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>