add missing break in inject_80211.c

Align the comment to code in inject_80211.c

inject_80211 uses notter/kuiper kernel files:
prepare for 802.11ax

NO code change. Formating

Update inject_80211 to avoid comiling error onboard

Set addr3 to addr1 for data/mgmt frame in inject_80211.c

Add more packet type and sub-type support into inject_80211.c

Change the example packet in inject_80211.c from broadcast to unicast to ease the loopback debug based on dmesg printing (broadcast packet is not printed)

To avoid compiling error of inject_80211.c with new kernel (2019_R2), the rand_char size needs to be 1484 due to the space occupied by u8aRadiotapHeader and ieee_hdr in buffer

Fix various typos

Found via codespell v2.1.dev0
`codespell -q 3 -L ans,filp,fils,hsi`

Update inject_80211.sh

Update inject_80211.h

Update inject_80211.c

Update analyze_80211.c

adding license and copyright headers

802.11 packet injector, analyzer and user guide