Add multi line support to color text generator

[Tofpu]

As the title says. The text area height gets automatically resized based on the content, and whenever the lines becomes too large for a particular preview, naturally it just excludes it.

Tested:

• Previews: all (Text, Sign, Book, Chat, MOTD, Name, Lore, Kick)
• Browser: Firefox and Edge
• Resolutions (via Firefox's Responsive Design Mode): Desktop (1440x2560) and Mobile (476x480).
• Functionalities:
  • The insert color (insertTextAtCursor) functionality seems to be working.
  • The copy button is copying the multi-line texts correctly.

Test input:

&1First Line
&2Second Line
&3Third Line
&4Fourth Line
&5Fifth Line

Demonstration:

[stephendotgg]

What a goat. When I was adding the 3 new previews I was going to add this but was much too lazy. Thank you for putting in the effort, it will not be forgotten.