Update input_raw_format default value

Documentation update for input_raw_format default value change from 0.3 to 0.5, following discussion within LHCb!3310 (merged) MR.
FYI: @dovombru

Should be merged with !1145 (merged), LHCb!3310 (merged), Allen!655 (merged), MooreAnalysis!72 (merged), lhcb-datapkg/PRConfig!211 (merged) and lhcb-datapkg/RawEventFormat!1 (merged).