Smk-py

- Added [MANIFEST.in](https://github.com/sahdjfg/smk-py/blob/main/MANIFEST.in).

- Fixed [setup.py](https://github.com/sahdjfg/smk-py/blob/main/setup.py).

- Added `.configure()`.

Usage

python
name = "world"

smk.feed([name])
smk.configure("demo.h.in")

- Added `smk.error`.

`smk.error` usage

python
import smk

sh = smk.check("sh")

if sh is None:
smk.error("sh is not available")


Console will look like below if `sh` is not available.

console
$ ./Makefile.py
[check] sh... no
error: sh is not available

- Updated the way to call `.replace()` in [setup.py](https://github.com/sahdjfg/smk-py/blob/main/setup.py).

- Implemented core functionality.