Document use of standard/docs/en/examples/merging/merge.py

[jpmckinney]

It updates standard/docs/en/examples/merging/merged.json and standard/docs/en/examples/merging/versioned.json but I don't know in what cases the files getting merged would change. Also, it seems like if it's run without first deleting those two files, it will effectively try to merge those files into themselves.

[jpmckinney]

It seems to have originated in this commit (can't find it in tree of parent commit): open-contracting/standard@42b4208

[jpmckinney]

@timgdavies Pinging so that we can hopefully close this issue :)

[jpmckinney]

Script is gone in open-contracting/standard#797