docs: Enhance/Refactor detecting kernel which name is same as venv

[dotpie]

Just for suggestion. From what I've observed, Molten use kernel name as a kernel ID. Therefore it display the default name of kernel in every environments, (python3 in conda) which make user confused. I refactor it based on the assumption that user installed a kernel inside of the project

Whether the user installs ipykernel or not, this logic searches for a kernel with the same name as the venv.
If not, it asks the user to select the kernel to connect to.

This PR intended following details:

• try_env_name: Turn getting env path logic into a function, enhance reusability.
• Slight changes of regex, ensure to find last dir/file of kernel_name.
• Give priority to env_ok at the condition statement, check if virtual env turned on. If so, load the kernel which named same with virtual environment first.

molten-242.mov