perf: use vim.fs.basename instead of shell basename (#10)

- also will not work on some windows systems who do not have something like wsl setup
- instead grab git full path and use lua to parse the basename

lua/gitpad/init.lua

@@ -52,7 +52,8 @@ function M.init_gitpad_file(opts)
   end
 
   -- create the repository directory if it doesn't exist
-  local repository_name = vim.fn.systemlist("bash -c 'basename `git rev-parse --show-toplevel`'")[1]
+  local repository_path = vim.fn.systemlist('git rev-parse --show-toplevel')[1]
+  local repository_name = vim.fs.basename(repository_path)
   local notes_dir = vim.fs.normalize(M.config.dir .. '/' .. repository_name)
 
   -- create the notes directory if it doesn't exist