infer/mod.rs: add doc comment to RFC1214 variant
infer/mod.rs: add doc comment to RFC1214 variant

aidancully/rust,GBGamer/rust,dwillmer/rust,GBGamer/rust,dwillmer/rust,graydon/rust,GBGamer/rust,dwillmer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust,GBGamer/rust,dwillmer/rust,graydon/rust,graydon/rust,GBGamer/rust,dwillmer/rust,dwillmer/rust,aidancully/rust,graydon/rust,GBGamer/rust,dwillmer/rust,dwillmer/rust,aidancully/rust,graydon/rust