Bugfix: Don't Start Server Right Away (#40)

This MR simplifies the plugin quite a bit by only attempting to start the Go server after you specifically try to run a command. This streamlines working on feature branches and removes the need for a `base_branch` property entirely.

lua/gitlab/state.lua

@@ -5,7 +5,6 @@ M.BIN               = nil
 M.PROJECT_ID        = nil
 M.ACTIVE_DISCUSSION = nil
 M.ACTIVE_NOTE       = nil
-M.BASE_BRANCH       = "main"
 M.keymaps           = {
   popup = {
     exit = "<Esc>",