merge SytzeH: Readme
merge SytzeH: Readme

Merge pull request #1449 from SytzeH/sql-layer/readme
https://github.com/FoundationDB/sql-layer/pull/1449

jaytaylor/sql-layer,qiuyesuifeng/sql-layer,ngaut/sql-layer,wfxiang08/sql-layer-1,qiuyesuifeng/sql-layer,ngaut/sql-layer,ngaut/sql-layer,relateiq/sql-layer,relateiq/sql-layer,jaytaylor/sql-layer,wfxiang08/sql-layer-1,relateiq/sql-layer,shunwang/sql-layer-1,ngaut/sql-layer,wfxiang08/sql-layer-1,relateiq/sql-layer,jaytaylor/sql-layer,qiuyesuifeng/sql-layer,qiuyesuifeng/sql-layer,shunwang/sql-layer-1,jaytaylor/sql-layer,wfxiang08/sql-layer-1,shunwang/sql-layer-1,shunwang/sql-layer-1