- Update `NAME` variable in Makefile to `thu-learn-downloader` to reflect the new name of the project.
- Add `MAMBA`, `RUN`, and `POETRY` variables to Makefile for easier management of dependencies and running commands.
- Modify the `docs` target in Makefile to use the `RUN` variable to run the `typer` command.
- Add a new `run` target in Makefile to run the `openssl.cnf` file using the `POETRY` variable.
- Update the `setup` target in Makefile to use the `MAMBA` variable to create a new conda environment with the necessary dependencies.
- Update the `$(ASSETS)/demo.png` target in Makefile to use the `RUN` variable to run the `vhs` command.
- Update the `$(DIST_TARGET)` target in Makefile to use the `RUN` variable to run the `python -m nuitka` command.
- Update the `$(DIST_TARGET)` target in Makefile to use the `RUN` variable to run the `pyinstaller` command.
- In `downloader.py`, add a `start` parameter to the `tqdm` progress bar to start the progress from 1 instead of 0.
- In `filename.py`, update the `filename` variable to include the `homework.number` in the filename stem.

This commit updates the Makefile to improve dependency management and command execution, and modifies the `downloader.py` and `filename.py` files to fix issues and improve functionality.