Mistake in readme

[Vyacheslav Lushin]

There is a little mistake in readme guide. In the description of the configuration file there is 'pg' key for the postgres connection and etc. This error follows:

root@9529452bd859:/home/go/pg2ch# go run main.go --config config.yaml
could not load config: publication name is not specified
exit status 1

If you look in the source file (pkg\config\config.go) there is different key 'postgres'
And if replace 'pg' with 'postgres', it works correctly.

[Murat Kabilov]

fixed.
thank you!