Fix things based on AR's feedback

Aadarsh Rajan did a review of the Tamil design. Apart from the #86 he has pointed out few things that we can fix before shipping Tamil. @enathu can you take a look at the pdf and see what you think? @kosalaya will work on implementing fixes.

[AbhayaLibre-Tamil-Test-16-10-Comments-AR.pdf](https://github.com/mooniak/abhaya-libre-font/files/13219023/AbhayaLibre-Tamil-Test-16-10-Comments-AR.pdf)
