* [TD-13307]<docs>: add description to docs index.

* fix the link of how to use taosBenchmark

* fix wrong links

* fix markdown format

* refine getting started section

* update

* fix install doc link

* fix chinese wording

* adjust section order

* adjust few format

* fix markdown format

* change logo

* replace logo with 50% smaller

* replace logo with 40% smaller

* replace logo with 327x80 smaller