Update from Upstream (#7)

* Use emoji heart on Linux and Mac

* Allow the user to type manim code when using - as filename.

Add log statements informing the user of what they must do.

* Automatically import manim if not imported.

Mention EOF macro for Windows as well.

* Clarify on which EOF macro is used by which OS.

* Add test for the dash-as-filename feature. (#4)

* Test by piping normal text to subprocess.

* Change ci.yml to test this branch.

* Simulate typing manim code by reading from file.

* Add file to read from.

* Skip test_dash_as_name, as it fails on Windows.

* Rename file used by dash test

* Removed an unnecessary function call.

Co-authored-by: Aathish Sivasubrahmanian <[email protected]>

Co-authored-by: Devin Neal <[email protected]>
Co-authored-by: Aathish Sivasubrahmanian <[email protected]>
Co-authored-by: Leo Torres <[email protected]>