refactor(installer): return function instead of M

lua/gopher/init.lua

···
 local tags = require "gopher.struct_tags"
 local gopher = {}
 
-gopher.install_deps = require("gopher.installer").install_all
+gopher.install_deps = require "gopher.installer"
 gopher.tags_add = tags.add
 gopher.tags_rm = tags.remove
 gopher.mod = require "gopher.gomod"

lua/gopher/installer.lua

···
 local Job = require "plenary.job"
-local M = {
-  urls = {
-    gomodifytags = "github.com/fatih/gomodifytags",
-    impl = "github.com/josharian/impl",
-  },
+local urls = {
+  gomodifytags = "github.com/fatih/gomodifytags",
+  impl = "github.com/josharian/impl",
 }
 
 local function install(pkg)
-  local url = M.urls[pkg] .. "@latest"
+  local url = urls[pkg] .. "@latest"
 
   Job
     :new({
···
 end
 
 ---Install required go deps
-function M.install_all()
-  for pkg, _ in pairs(M.urls) do
+return function()
+  for pkg, _ in pairs(urls) do
     install(pkg)
   end
 end
-
-return M