Add configuration for vim

- Add ~/.config/vim/vimrc
  + Configure basic stuff
  + Activate spell checks
  + Activate syntax highlighting and ruler
  + Show whitespace characters
  + Add various snippets for mouse handling,
    toggling line numbers, and search
  + Set `vim`-related directories inside
   ~/.config/vim and ~/.local/state/vim
- Integrate extra settings for Python files
  in ~/.config/vim/after/ftplugin/python.vim
  and ~/.config/vim/after/syntax/python.vim
- Add `vim` artifacts in ~/.config/git/ignore

.config/git/ignore

@@ -12,3 +12,24 @@ __pycache__/
 .venv/
 venv/
 .env
+
+# Vim
+# Source: https://github.com/github/gitignore/blob/main/Global/Vim.gitignore
+#
+# Swap
+[._]*.s[a-v][a-z]
+!*.svg
+[._]*.sw[a-p]
+[._]s[a-rt-v][a-z]
+[._]ss[a-gi-z]
+[._]sw[a-p]
+# Session
+Session.vim
+Sessionx.vim
+# Temporary
+.netrwhist
+*~
+# Auto-generated tag files
+tags
+# Persistent undo
+[._]*.un~