* [DOC][cherry-pick] update paddle lite docs (#4347)

* [DOC] update paddle lite docs (#4329)

* [DOC] fix doc of support models tutorials and arch, test=develop, test=document_fix

* [DOC] update architecture, test=develop, test=document_fix

* [DOC] some updates based on v2.6, test=develop, test=document_fix

* [DOC] update based on v2.7, test=document_fix