docs(README): add "Which chips can be simulated"

Author: urish

README.md

@@ -19,7 +19,7 @@ A step-by-step video tutorial showing how to build a simple Arduino simulator us
 
 [![AVR8JS Walkthrough Video](https://i.imgur.com/3meSd1m.png)](https://youtu.be/fArqj-USmjA)
 
-### Unofficial Examples
+### Unofficial examples
 
 * [Minimal Example](https://stackblitz.com/edit/avr8js-minimal?file=main.ts)
 * [6 LEDs](https://stackblitz.com/edit/avr8js-6leds?file=index.ts)
@@ -29,9 +29,20 @@ A step-by-step video tutorial showing how to build a simple Arduino simulator us
 * [Arduino MEGA NeoPixel Matrix](https://stackblitz.com/edit/avr8js-mega-ws2812?file=index.ts)
 * [Simon Game](https://stackblitz.com/edit/avr8js-simon-game?file=index.ts) - with pushbuttons and sound
 * [XMAS LEDs](https://stackblitz.com/edit/avr8js-xmas-dafna?file=index.ts)
-* [ATtiny85 Simulation](https://avr8js-attiny85.stackblitz.io?file=index.ts)
 * [Assembly Code](https://stackblitz.com/edit/avr8js-asm?file=index.ts)
 
+## Which chips can be simulated?
+
+The library focuses on simulating the *ATmega328p*, which is the MCU used by the Arduino Uno.
+
+However, the code is built in a modular way, and is highly configurable, making it possible
+to simulate many chips from the AVR8 family, such as the ATmega2560 and the ATtiny series:
+
+* [ATtiny85 Simulation](https://avr8js-attiny85.stackblitz.io?file=index.ts)
+
+Check out [issue 67](https://github.com/wokwi/avr8js/issues/67#issuecomment-728121667) and
+[issue 73](https://github.com/wokwi/avr8js/issues/73#issuecomment-743740477) for more information.
+
 ## Running the tests
 
 Run the tests once: