Feat: Add token counting

[Angelchev]

Closes: #41

Overview

• Add command to count tokens from a visual selection.
• Add python script to count tokens with OpenAI's tiktoken.
• Add utils.vim to launch python scripts more easily.
• Add automatic venv setup for Neovim with lazy.nvim package manager via build.lua.
  • Create a python virtual environment automatically for Linux or Windows (Untested).
  • Install dependencies from requirements.txt automatically.
• Add Neovim animated notification integration with nvim-notify.

Todo

• Add python test for new script
• Check for tiktoken dependency in Python script, and throw error if not present.
• Investigate automatically setting up python venv and installing requirements for vim 8.
• Update README.md to document optionally setting up python venv.
• Update vimdocs:
  • New command and availability dependant on tiktoken
  • Integration of nvim-notify

Testing

• Test automatic setup for Neovim with lazy.nvim.
  • Linux
  • Mac OSX
  • Windows

Screenshots

Neovim Animated Notifications via nvim-notify

Automatic venv setup for Neovim with lazy.nvim