fix sorting order by dhatu

[vipranarayan14]

Current sort order by dhatu:

1. अकि (अकि) लक्षण
2. अकिँ॒ (अक्) लक्षण
3. अकँ (अक्) कुटिलायां_गतौ

But should be:

1. अकँ (अक्) कुटिलायां_गतौ
2. अकि (अकि) लक्षण
3. अकिँ॒ (अक्) लक्षण

Fix:

• Use sorter from here: https://anubhav-chattoraj.github.io/indic-tools/devanagari_sorter/
• Or use any other algos discussed here: https://groups.google.com/g/sanskrit-programmers/c/HTyINaNbvUQ

[vipranarayan14]

The problem is, the list is sorted using the dhatu field but it was expected to be sorted using muladhatu field.
Changing to muladhatu should fix it.