export getLocaleConfig and update docs

[naquiroz]

Problem

cleanValue asks for values that are quite hard to get, but those are easily obtainable with the already done function getLocaleConfig.

Solution

Export the getLocaleConfig as part of the package, plus add it to the docs.

Additional changes

• Added cleanValue to the README.md
• Added formatValueOnBlur to the README.md since it was missing.