Support more languages for scheme Info

[subins2000]

Varnam online editor has a scheme information section to show all letter mappings. This currently only works good for Malayalam: https://varnamproject.github.io/editor/#/scheme?tab=scheme

To add support for other languages, will need to add the alphabet table of the language to the source code. Here is the part to add alphabets: https://github.com/varnamproject/varnamd-govarnam/blob/master/scheme.go#L114

The part to add code: https://github.com/varnamproject/varnamd-govarnam/blob/master/scheme.go#L104

You will need to make functions for other language similar to getMLConsonants()