refactor: use vim.system instead of pleanry (#85)

* refactor!: migrate to vim.system

* refactor(gotests): use vim.system

* refactor(iferr): use vim.system

* refactor(impl): use vim.system

* refactor(installer): use vim.system and add sync mode

* test: fix gotests' tests

* refactor(struct_tags): use vim.system

* chore(ci): install all deps explicitly

* refactor(installer)!: add sync as an option

* docs: update readme

README.md

@@ -13,17 +13,15 @@ It's **NOT** an LSP tool, the main goal of this plugin is to add go tooling supp
 Requirements:
 
 - **Neovim 0.10** or later
-- `go` treesitter parser, install by `:TSInstall go`
+- Treesitter `go` parser(`:TSInstall go`)
 - [Go](https://github.com/golang/go) installed (tested on 1.23)
 
 ```lua
 {
   "olexsmir/gopher.nvim",
   ft = "go",
-  -- branch = "develop", -- if you want develop branch
-                         -- keep in mind, it might break everything
+  -- branch = "develop"
   dependencies = {
-    "nvim-lua/plenary.nvim",
     "nvim-treesitter/nvim-treesitter",
   },
   -- (optional) will update plugin's deps on every update