Setup state logic of preact component

[TimDaub]

Scope

• This issue is supposed to be done after we have created a test environment with #4.
• Now that we can look at our preact component in the browser, it's time to build the functionality
• As is outlined in #1, we want the component to be a <input> that is "sandwiched" by two buttons e.g.

Deliverables

<button value="-" />
<input type="number" value="1" />
<button value="+" />

• If the user clicks the +, we want the value of input to increase. If they click -, we want the value to decrease.
• If the user clicks/focuses on the input, we want them to be able to change the value using the keyboard too
• There should be a min and a max value that we can define. These dictate how high or low the value you can possibly go.

Time estimate

3h

[TimDaub]

Fixed in #9