docs, tests: replace runnable examples with testable example and update README

Author: vakhov

README.md

@@ -6,6 +6,22 @@
 [![Telegram EN][telegram-badge]][telegram-en-url]
 [![Telegram RU][telegram-badge]][telegram-ru-url]
 
+## Table of contents
+
+- [go-tlog](#go-tlog)
+  - [Features](#features)
+  - [Installation](#installation)
+  - [Quick start](#quick-start)
+  - [Configuration](#configuration)
+    - [type Opts](#type-opts)
+    - [Main API](#main-api)
+  - [Log levels](#log-levels)
+  - [Output formats](#output-formats)
+  - [Output destinations](#output-destinations)
+  - [Examples](#examples)
+  - [Testing](#testing)
+  - [License](#license)
+
 # go-tlog
 
 `go-tlog` is a lightweight and configurable logging library for Go applications.  
@@ -133,41 +149,11 @@ Supported targets:
 
 ## Examples
 
-Ready-to-run examples are located in the `_examples/` directory:
-
-```
-_examples/
- ├── stdout/
- │   └── main.go
- ├── stderr/
- │   └── main.go
- ├── file/
- │   └── main.go
- └── multi/
-     └── main.go
-```
+Included examples:
 
-Run examples:
-
-```bash
-# Example 1 — log to STDOUT in text format
-go run ./_examples/stdout
-
-# Example 2 — log to STDERR in JSON format
-# Redirect stderr to a file and inspect its contents
-go run ./_examples/stderr 2> logs.json
-cat logs.json
-
-# Example 3 — log to a file in /tmp directory
-# The file will be created automatically if it doesn’t exist
-go run ./_examples/file
-cat /tmp/tlog_demo/app.log
-
-# Example 4 — log to multiple destinations (stdout + file)
-# This writes the same log entry both to console and to /tmp/tlog_multi/app.log
-go run ./_examples/multi
-cat /tmp/tlog_multi/app.log
-```
+- **ExampleNew_text** — basic text logger writing to stdout  
+- **ExampleNew_json** — JSON logging  
+- **ExampleNew_multi** — logging to multiple destinations (`stdout,/tmp/...`)
 
 Each example demonstrates different combinations of Path, Format, and Level,
 including how to log to multiple outputs at the same time.
@@ -177,7 +163,7 @@ including how to log to multiple outputs at the same time.
 ## Testing
 
 ```bash
-go test ./...
+make test
 ```
 
 ---

_examples/file/main.go

@@ -0,0 +1,58 @@
+package tlog_test
+
+import (
+	"log/slog"
+
+	"github.com/tarantool/go-tlog"
+)
+
+// ExampleNew_text shows how to create a text logger that writes to stdout.
+func ExampleNew_text() {
+	log, err := tlog.New(tlog.Opts{
+		Level:  tlog.LevelInfo,
+		Format: tlog.FormatText,
+		Path:   "stdout",
+	})
+	if err != nil {
+		panic(err)
+	}
+	defer func() { _ = log.Close() }()
+
+	logger := log.Logger().With(slog.String("component", "example_text"))
+	logger.Info("service started")
+}
+
+// ExampleNew_json shows how to create a JSON logger that writes to stdout.
+func ExampleNew_json() {
+	log, err := tlog.New(tlog.Opts{
+		Level:  tlog.LevelInfo,
+		Format: tlog.FormatJSON,
+		Path:   "stdout",
+	})
+	if err != nil {
+		panic(err)
+	}
+	defer func() { _ = log.Close() }()
+
+	logger := log.Logger().With(
+		slog.String("component", "example_json"),
+		slog.String("request_id", "abc-123"),
+	)
+	logger.Error("request failed")
+}
+
+// ExampleNew_multi shows how to log to multiple destinations at once.
+func ExampleNew_multi() {
+	log, err := tlog.New(tlog.Opts{
+		Level:  tlog.LevelInfo,
+		Format: tlog.FormatText,
+		Path:   "stdout,/tmp/tlog_example_multi.log",
+	})
+	if err != nil {
+		panic(err)
+	}
+	defer func() { _ = log.Close() }()
+
+	logger := log.Logger().With(slog.String("component", "example_multi"))
+	logger.Info("message written to stdout and file")
+}