Add docs to lib.rs
Add docs to MyPool
Add docs to MyPooledConn
Add docs to MyOpts
Add docs to MyPool#get_conn
Add docs to MyConn
Remove unnecessary backticks from docs
Add some links to docs
Add docs for `Stmt`
Add `Stmt#params_ref` and `Stmt#columns_ref`
Use `enumerate` instead of `zip` for `QueryResult#column_index`
Add `Stmt#column_index`
Add docs for `Column`
Add docs for `QueryResult`
Update for rust nightly