Rename repositories

[kaizu]

• [x] ecell4 -> ecell4-base (ecell4_base)
• [x] ecell4-extras -> ecell4
• [x] ecell4-notebooks -> ecell4-docs

[kaizu]

The python packages are renamed as ecell4 and ecell4_base (4 is included in the name).

Along with this, the version number is reset. Previously we released several versions like v4.2.0. However, the next release scheduled as v4.2 would be v1.0.0 of ecell4.

• Before: ecell (v4.2.0)
• After: ecell4 (v1.0.0) and ecell4_base (v1.0.0)

For the time being, ecell will be maintained as before.

• https://pypi.org/project/ecell/
• https://pypi.org/project/ecell4-base/
• https://pypi.org/project/ecell4/

[kaizu]

It might be better to redirect ecell to ecell4 on PyPI.