readme: add logo to landing page

Author: AldoGl

README.md

@@ -1,4 +1,13 @@
-# ABCredit.jl
+<div align='center'>
+<picture>
+  <source media="(prefers-color-scheme: dark)" srcset="https://raw.githubusercontent.com/bancaditalia/ABCredit.jl/main/docs/logo/logo_white_text.png">
+  <source media="(prefers-color-scheme: light)" srcset="https://raw.githubusercontent.com/bancaditalia/ABCredit.jl/main/docs/logo/logo_black_text.png">
+  <img alt="Logo adapts to light and dark modes" src="https://raw.githubusercontent.com/bancaditalia/ABCredit.jl/main/docs/logo/logo_black_text.png" width="500">
+</picture>
+<sup><a href="#footnote-1">*</a></sup>
+</div>
+
+# The ABC of macroeconomic agent-based modelling
 
 A fast and easy to use Julia implementation of the model described in [_Emergent dynamics of a macroeconomic agent based model with capital and credit_](https://www.sciencedirect.com/science/article/abs/pii/S0165188914001572).
 The package can be used to simulate the original model or as a base for extensions. If you are not familiar with Julia and the way in which multiple dispatch allows for powerful extensions, don't hesitate to get in touch!
@@ -52,3 +61,7 @@ If you found this package useful for your research, please cite the following pu
 
 This package is an outcome of a research project. All errors are those of
 the authors. All views expressed are personal views, not those of Bank of Italy.
+
+<p id="footnote-1">
+* Credits to <a href="https://www.bankit.art/people/sara-corbo">Sara Corbo</a>  for the logo, echoing the logo of <a href="https://github.com/bancaditalia/BeforeIT.jl">BeforeIT</a> but with warmer colors.
+</p>