sendEmail fonction help for making it look good!

I use the sendEmail code in a button, but I want to know what are the text alteration I can do like center, color, size, Is there a list somewhere? .. I discovered that *text* makes it bold! I would also need a line.

And I dont know how to make text jump only to the next line and not making a double line jump each time I make an "enter".

Exemple of a list: ( I want it to to look like that)
apple
tomatoe
citrus

But it looks like that:

apple

tomatoe

citrus

Thanks!