add korean word module to hd mnemonic

[ChrisCho-H]

Korea is one of the largest in terms of the number of users in crypto.
I refer to bip39.js where Korean support is implemented.
expect zero harm with useful utility.

[theanmolsharma]

I'd like to see some tests before we get it merged.

[ChrisCho-H]

I've tested and it works well!
You can try mnemonic-test to verify.

[theanmolsharma]

Tested ACK.
Before we merge, I'd like you to squash all commits into a single commit.

[ChrisCho-H]

alright

[codecov]

Codecov Report

Patch coverage: 50.00% and no project coverage change.

Comparison is base (b005869) 69.55% compared to head (49a0cca) 69.56%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1158   +/-   ##
=======================================
  Coverage   69.55%   69.56%           
=======================================
  Files         158      159    +1     
  Lines       26603    26607    +4     
=======================================
+ Hits        18505    18509    +4     
  Misses       8098     8098           

Impacted Files	Coverage Δ
lib/hd/mnemonic.js	82.14% <ø> (ø)
lib/hd/wordlist-browser.js	0.00% <0.00%> (ø)
lib/hd/words/index.js	0.00% <0.00%> (ø)
lib/hd/wordlist.js	90.90% <100.00%> (+10.90%)	⬆️
lib/hd/words/korean.js	100.00% <100.00%> (ø)

... and 2 files with indirect coverage changes

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[pinheadmz]

Where is the word list from? I don't understand the language but it doesn't look like it matches

https://github.com/bitcoinjs/bip39/blob/master/src/wordlists/korean.json

or

https://github.com/bitcoin/bips/blob/master/bip-0039/korean.txt

Same question about the test vectors, where are those from?

[ChrisCho-H]

It's same with the former one(bitcoinjs/bip39).
Test vector is just generated from given seed, and the phrase is one in the wordlist.

[pinheadmz]

ah ok, its just the rendering that confused me,

compare https://github.com/bitcoinjs/bip39/blob/master/src/wordlists/korean.json
to https://raw.githubusercontent.com/bitcoinjs/bip39/master/src/wordlists/korean.json

[pinheadmz]

ok please just fix the lint error (single quotes)

[ChrisCho-H]

line error fixed