pig-latin: regenerate README (#467)
pig-latin: regenerate README (#467)

The new rules add additional detail.

The update was discussed in the problem-specifications repo in PR #1171:
pig-latin improve documentation

https://github.com/exercism/problem-specifications/pull/1171

Resolves https://github.com/exercism/rust/issues/453
petertseng/exercism-rust,petertseng/exercism-rust,petertseng/exercism-rust,exercism/xrust,exercism/xrust