TOML Support in NeBuild

I just added TOML support in NeBuild (https://github.com/nekernel-org/nebuild/tree/dev)

Here's how it looks:

compiler_path = "g++"
compiler_std = "c++20"
headers_path = [ "lib" ]
sources_path = [ "hello_world.cc" ]
output_name = "hello_world.elf"
compiler_flags = [ "-fPIC" ]
cpp_macros = [ "FOO_MACRO" ]
run_after_build = true

EXAMPLE: https://github.com/nekernel-org/nebuild/tree/dev/examples/example_03_hello_world_toml

BONUS: Also fixed many issues in the develop branch of NeBuild.

Amlal.