Outdated encoding for Malayalam sample

[asmusf]

https://github.com/unicode-org/unilex/blob/master/data/frequency/ml.txt

This file is encoded with the Unicode 5.0 and earlier encoding for Chillu characters. (See Chapter 12 of Unicode 10.0).

[behnam]

IIUC, a normalization table can be used, as show in Table 12-37. Atomic Encoding of Malayalam Chillus https://www.unicode.org/versions/Unicode10.0.0/ch12.pdf#page=65.

[asmusf]

I think the file should be replaced with one that uses the atomic encoding. Another issue is the use of U+0D4C which I understand is considered outdated. (Other corpora I've encountered recently do not have the latter issue).

[brawer]

If you don’t mind, could you send a pull request to fix the problem?