Refactor sql readme.md (#2640)
Refactor sql readme.md (#2640)

* Refactor sql readme.md

- Rename schema-* to package-pure-* in order to follow convention for python multi-version
- Rename package-2017-10-preview to package-composite-v1. The reasons for this are explained in package-2017-03-01-preview tag. The next tag that I add in the near future will be package-composite-v2, which will represent a breaking change & major version bump for clients.
- Improved description of various sections
- Whitespace/header consistency

* Added package-pure-2017-10 including Go support

* Commented on Go api-versions

* Removed bad python section

* Fixed typo in 2017-10 go package

yugangw-msft/azure-rest-api-specs,akshaysngupta/azure-rest-api-specs,AsrOneSdk/azure-rest-api-specs,hovsepm/azure-rest-api-specs,AsrOneSdk/azure-rest-api-specs,d3r3kk/azure-rest-api-specs,henry416/azure-rest-api-specs,deathly809/azure-rest-api-specs,yaakoviyun/azure-rest-api-specs,amarzavery/azure-rest-api-specs,johanste/azure-rest-api-specs,kiwidev/azure-rest-api-specs,Nking92/azure-rest-api-specs,dmakwana/azure-rest-api-specs,brjohnstmsft/azure-rest-api-specs,jobatzil/azure-rest-api-specs,yugangw-msft/azure-rest-api-specs,naveedaz/azure-rest-api-specs,olydis/azure-rest-api-specs,Nking92/azure-rest-api-specs,Nking92/azure-rest-api-specs,hyonholee/azure-rest-api-specs,AppPlatPerf/azure-rest-api-specs,naveedaz/azure-rest-api-specs,AuxMon/azure-rest-api-specs,vladrai/azure-rest-api-specs,AppPlatPerf/azure-rest-api-specs,AuxMon/azure-rest-api-specs,solankisamir/azure-rest-api-specs,henry416/azure-rest-api-specs,kiwidev/azure-rest-api-specs,amarzavery/azure-rest-api-specs,brjohnstmsft/azure-rest-api-specs,hovsepm/azure-rest-api-specs,solankisamir/azure-rest-api-specs,vladrai/azure-rest-api-specs,hyonholee/azure-rest-api-specs,felixwa/azure-rest-api-specs,nathannfan/azure-rest-api-specs,JasonYang-MSFT/azure-rest-api-specs,deathly809/azure-rest-api-specs,johanste/azure-rest-api-specs,dashimi16/azure-rest-api-specs,yaakoviyun/azure-rest-api-specs