[TD-3116]Fix dead lock issue

[TD-3155]fix meta retry issue

[TD-3110]<fix>: TSDB_MIN_WAL_LEVEL <- 0 to allow db wal no log

[TD-3167]<fix>: fix cannot use chinese charset in docker images

[TD-3158]<fix>: replace head_type with column_meta in http response

[TD-3154]<test>: update test case

[TD-3161]<test>add coverage on unsigned type

[TD-3127]<test>add unsigned type

[TD-3124]<fix>: stop & free TAOS_RES *result post http queue shutdown

[TD-3042]<fix>: fix unsigned to signed conversion with serverPort

[TD-3043]<fix>: allow monitor db table to be dropped & altered

[TD-3158]<enhance>: add head_type fileds with RESTful API

[TD-3154]<hotfix>: fix invalid write

Hotfix/td 3096

[TD-3164]<fix>replace sub table name error

[TD-3160] <fix>: fix c demo program compile issue.

<Doc>:fix FAQ doc-en

[TD-3157] <docs>: update readme regarding host arch detecting.

Signed-off-by: Njyz0309 <45495947@qq.com>

Update docs.md