feat(molten-nvim): enhance molten config and add custom init function and statusline

[tku137]

📑 Description

This plugin config adds a custom init function for Python venvs. When calling <Leader>mmp, we check if a venv is activated. If it is, we check if a jupyter kernel spec for this venv already exists and :MoltenInit this kernel spec. If no kernel spec is found, we prompt for a unique name, create the kernel spec and :MoltenInit it.

It also adds a status line indication if molten is activated and what kernel is initialized.

Last but not least, I added some more useful keymaps and altered the existing one slightly as well as give a hint in the readme about setting the python3_host_prog variable in AstroNVim.

[github-actions]

Review Checklist

Does this PR follow the [Contribution Guidelines](development guidelines)? Following is a partial checklist:

Proper conventional commit scoping:

• If you are adding a new plugin, the scope would be the name of the category it is being added into. ex. feat(utility): added noice.nvim plugin

• If you are modifying a pre-existing plugin or pack, the scope would be the name of the plugin folder. ex. fix(noice-nvim): fix LSP handler error

• Pull request title has the appropriate conventional commit type and scope where the scope is the name of the pre-existing directory in the project as described above

• README is properly formatted and uses fenced in links with <url> unless they are inside a [title](url)

• Entry returns a single plugin spec with the new plugin as the only top level spec (not applicable for recipes or packs).

• Proper usage of opts table rather than setting things up with the config function.

• Proper usage of specs table for all specs that are not dependencies of a given plugin (not applicable for recipes or packs).

[tku137]

Anything I can do to get a forward with this PR?

[Uzaaft]

Anything I can do to get a forward with this PR?

One of the maintainers just need to take the time out of their day to review it.