feat: add gomodifytags support

lua/gopher/_utils/init.lua

@@ -0,0 +1,22 @@
+return {
+  ---@param t table
+  ---@return boolean
+  empty = function(t)
+    if t == nil then
+      return true
+    end
+
+    return next(t) == nil
+  end,
+
+  ---@param s string
+  ---@return string
+  rtrim = function(s)
+    local n = #s
+    while n > 0 and s:find("^%s", n) do
+      n = n - 1
+    end
+
+    return s:sub(1, n)
+  end,
+}