Fix link on main Readme

[nikoloiosifovich]

Hello everyone!

I'm getting error 404 when try to access Tabela de Permissões, please fix this. ;D

fix line 14 link:
- <a href="/frontend/FUNC_PERMISSION.md">Tabela de Permissões</a>
to
- <a href="/frontend/README.md">Tabela de Permissões</a>

Bye!!!