docs: add logo, center header and badges, fix code blocks

Added assertpy2 SVG logo. Centered title, tagline and badges.
Fixed code block syntax highlighting for error output examples.
Merged bare assert comparison into a single code block.

Author: Solganis

README.md

@@ -1,13 +1,20 @@
-# assertpy2
+<p align="center">
+  <img src="docs/logo.svg" alt="assertpy2" width="280">
+</p>
 
-Fluent assertion library for Python with full type safety and soft assertions. Maintained fork of [assertpy](https://github.com/assertpy/assertpy).
+<p align="center">
+  Fluent assertion library for Python with full type safety and soft assertions.<br>
+  Maintained fork of <a href="https://github.com/assertpy/assertpy">assertpy</a>.
+</p>
 
-[![CI](https://github.com/Solganis/assertpy2/actions/workflows/ci.yml/badge.svg)](https://github.com/Solganis/assertpy2/actions/workflows/ci.yml)
-[![PyPI version](https://img.shields.io/pypi/v/assertpy2)](https://pypi.org/project/assertpy2/)
-[![Downloads](https://static.pepy.tech/badge/assertpy2/month)](https://pepy.tech/projects/assertpy2)
-[![Python](https://img.shields.io/pypi/pyversions/assertpy2)](https://pypi.org/project/assertpy2/)
-[![Coverage](https://img.shields.io/badge/coverage-100%25-brightgreen)](https://github.com/Solganis/assertpy2)
-[![License](https://img.shields.io/github/license/Solganis/assertpy2)](https://github.com/Solganis/assertpy2/blob/main/LICENSE)
+<p align="center">
+  <a href="https://github.com/Solganis/assertpy2/actions/workflows/ci.yml"><img src="https://github.com/Solganis/assertpy2/actions/workflows/ci.yml/badge.svg" alt="CI"></a>
+  <a href="https://pypi.org/project/assertpy2/"><img src="https://img.shields.io/pypi/v/assertpy2" alt="PyPI version"></a>
+  <a href="https://pepy.tech/projects/assertpy2"><img src="https://static.pepy.tech/badge/assertpy2/month" alt="Downloads"></a>
+  <a href="https://pypi.org/project/assertpy2/"><img src="https://img.shields.io/pypi/pyversions/assertpy2" alt="Python"></a>
+  <a href="https://github.com/Solganis/assertpy2"><img src="https://img.shields.io/badge/coverage-100%25-brightgreen" alt="Coverage"></a>
+  <a href="https://github.com/Solganis/assertpy2/blob/main/LICENSE"><img src="https://img.shields.io/github/license/Solganis/assertpy2" alt="License"></a>
+</p>
 
 
 ## Quick start
@@ -30,7 +37,7 @@ def test_user():
 
 When an assertion fails, the error message tells you exactly what went wrong:
 
-```
+```py
 assert_that(user["age"]).is_between(50, 120)
 # AssertionError: Expected <30> to be between <50> and <120>, but was not.
 
@@ -49,9 +56,7 @@ assert user["age"] >= 18
 # assertpy2 - same check, clear failure message
 assert_that(user["age"]).is_greater_than_or_equal_to(18)
 # AssertionError: Expected <16> to be greater than or equal to <18>, but was not.
-```
 
-```py
 # bare assert - three separate statements
 assert isinstance(items, list)
 assert len(items) == 3