Add example link in README.md - Template and Config

[Yang09701194]

In README.md - Template and Config,

I suggest add example direction to https://github.com/go-xorm/cmd/tree/master/xorm/templates

such as the bold word in the end below,

because when I see this paragraph at the first time, I can't know what's the name of config file, what's the name of template file, etc.

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Template and Config

Now, xorm tool supports go and c++ two languages and have go, goxorm, c++ three of default templates. In template directory, we can put a config file to control how to generating.

lang=go
genJson=1

lang must be go or c++ now. genJson can be 1 or 0, if 1 then the struct will have json tag.

Complete example see https://github.com/go-xorm/cmd/tree/master/xorm/templates