Move examples to examples dir, now LoadJsonFile() also returns err

* Move examples from cmd to examples dir
* Update Makefile
* LoadJsonFile() dies in-place on read or parse error which is not correct
* LoadJsonFile() wastes Instance map, now it returns its own map and error if any

cmd/01-LoadJsonFile/main.go

@@ -1,21 +0,0 @@
-package main
-
-import (
-	"doll/internal/doll"
-	"doll/internal/log"
-	"os"
-
-	"github.com/davecgh/go-spew/spew"
-)
-
-func main() {
-	log.Init("info", os.Stderr)
-	log.Info("loading config.json")
-
-	data := doll.LoadJsonFile("test_data/config.json")
-
-	log.Info("data fron config.json is")
-	spew.Dump(data)
-}
-
-/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */

cmd/02-TestLuaScript/main.go

@@ -1,34 +0,0 @@
-package main
-
-import (
-	"doll/internal/log"
-	"os"
-
-	lua "github.com/yuin/gopher-lua"
-)
-
-func main() {
-	log.Init("info", os.Stderr)
-
-	L := lua.NewState()
-	defer L.Close()
-
-	// Load the Lua script file.
-	log.Info("Loading ./test_data/01-test.lua")
-
-	luaCode, err := os.ReadFile("./test_data/01-test.lua")
-
-	if err != nil {
-		log.Errorf("Error reading Lua file: %s", err)
-
-		os.Exit(1)
-	}
-
-	if err := L.DoString(string(luaCode)); err != nil {
-		log.Errorf("Error evaluating Lua code: %s", err)
-
-		os.Exit(1)
-	}
-}
-
-/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */