Clarify schedule table guidance

[fletching]

sch_lab_table.c has some guidance for creating the scheduling table, including "Make sure the table is terminated by the SCH_LAB_END_OF_TABLE entry". But In looking at the file history, it doesn't look like the default schedule table has included a SCH_LAB_END_OF_TABLE entry ever in the past year, which is as far back as that file history goes. Should that guidance be removed?

[skliper]

The loop is below, and skips entries with a PacketRate == 0. No longer need to terminate the table with SCH_LAB_END_OF_TABLE.

sch_lab/fsw/src/sch_lab_app.c

Lines 123 to 135 in fdc1ed1

	for (i = 0; i < SCH_LAB_MAX_SCHEDULE_ENTRIES; i++)
	{
	if (LocalStateEntry->PacketRate != 0)
	{
	++LocalStateEntry->Counter;
	if (LocalStateEntry->Counter >= LocalStateEntry->PacketRate)
	{
	LocalStateEntry->Counter = 0;
	CFE_SB_SendMsg(&LocalStateEntry->MsgBuf.MsgHdr);
	}
	}
	++LocalStateEntry;
	}

I'll submit a PR.