The connector for rust has been updated to use `deadpool` as default connection pool instead of `r2d2`, and the `r2d2` was only kept for blocking mode.

* docs: add rest api diff

* docs: use html table

* docs: use json instead of table in rest api doc

* docs: add rest api diff

* docs: use html table

* docs: add taoskeeper start as service

* docs: update taoskeer launch

* docs: this line is inaccurate, in current connector-python repo, it require python >= 3.6.2 because there is a dependence iso8601

* docs: append websocket doc for python connector

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Co-authored-by: NAdam Ji <jrgwyz@163.com>

* docs: add directions of mac uninstall

* docs: reformat

* docs: add new line

* docs: add new line