Add language list to README

README.md

@@ -1,7 +1,30 @@
 bip39
 =====
 
-A Rust implementation of BIP-39 mnemonic codes.
+A Rust implementation of [BIP-39](https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki)
+mnemonic codes.
+
+
+## Word lists (languages)
+
+We support all languages
+[specified in the BIP-39 standard](https://github.com/bitcoin/bips/blob/master/bip-0039/bip-0039-wordlists.md)
+as of writing.
+
+The English language is always loaded and other languages can be loaded using the corresponding feature.
+
+Use the `all-languages` feature to enable all languages.
+
+- English (always enabled)
+- Simplified Chinese (`chinese-simplified`)
+- Traditional Chinese (`chinese-traditional`)
+- Czech (`czech`)
+- French (`french`)
+- Italian (`italian`)
+- Japanese (`japanese`)
+- Korean (`korean`)
+- Spanish (`spanish`)
+
 
 ## MSRV