Table 2-1: Update the description of V_BCKP pin;
Chapter 3.3: Add requirement of V_BCKP;
Chapter 1.3: Add the description of external interfaces;
Add chapter 3.1: Recommended Minimal Design;
Table 2-4: Update the IO threshold;
3.2 Antenna Feed Design: D1 and D4 should support high
frequency signals (above 2000 MHz);
Chapter 5.2: Update the description of the humidity indicator;
Table 1-1: Update the heading accuracy (0.1° /1m baseline)
Add Chapter 3.5 Recommended PCB Package Design;
Optimize Chapter 3.2 Antenna Feed Design;
Optimize Chapter 3.3 Power-on and Power-off