Chore: UX improvements for arguments passing

[remybar]

Related to #43.

I've added a new Modal component to be able to show some popups easily.
I've checked on mobile and it is correctly displayed (with a smaller font size).

Don't hesitate to tell me if something has to be changed !

[mazurroman]

Thanks @remybar !

Some small improvements pls:

• Can you add an "X" button to the top right of the modal, which will close the modal? We can use the same "X" style as we have in the top banner called "About cairovm.codes"
• In the modal you call it "arguments" but in the input it's called "parameters...". Let's make it consistent and only use one word
• Let's make the "?" icon more subtle. It's not an important element on the screen so it doesn't need to be very noisy. I suggest to use a dark gray color (maybe same color as the color for "Enter program parameters..."). We can probably also make the icon smaller and with thinner lines — similar to the permalink icon.

[remybar]

Thanks @remybar !

Some small improvements pls:

* [ ]  Can you add an "X" button to the top right of the modal, which will close the modal? We can use the same "X" style as we have in the top banner called "About cairovm.codes"

* [ ]  In the modal you call it "arguments" but in the input it's called "parameters...". Let's make it consistent and only use one word

* [ ]  Let's make the "?" icon more subtle. It's not an important element on the screen so it doesn't need to be very noisy. I suggest to use a dark gray color (maybe same color as the color for "Enter program parameters..."). We can probably also make the icon smaller and with thinner lines — similar to the permalink icon.

Yes, I agree !
I did these modifications. Tell me if the "?" icon is small/thin enough for you ;-) I decreased its size a little bit and I tried to make it thinner but I'm not sure it is possible as the stroke-width attribute seems ignore 🤔

[mazurroman]

looking good!