[yocto] Yocto weekly bug trend charts -- WW20

[Xu, Jiajun]

Hi all,
	From this week, QA will maintain a wiki page to save weekly bug trend charts for Yocto. The wiki page URL is https://wiki.pokylinux.org/wiki/Yocto_Bug_Trend. There are lots of bugs are fixed in WW20, while more new bugs are submitted. The open bug number increased to 180. Weekly meta-intel BSPs testing is still BLOCKED because autobuilder does not build them.

Best Regards,
Jiajun