Add small backwards-compatible features to language, improve editing experience

[cyderize]

These changes are deployed here.

Bug fixes:

• Fix a bug where long output in the output window was unable to be scrolled all the way to the top

Language changes:

• Change the 0xA opcode to LoadImmi X, which loads a 12-bit unsigned immediate value into the AC.
• Change Clear to be an alias for LoadImmi 0
• Allow using 0C00 as the operand for SkipCond to allow for skipping when the AC is non-zero.

Editor features:

• Add an instruction set button to the toolbar which shows help for syntax and instructions
• Enable using Ctrl+/ to toggle line comments
• Allow auto-complete to appear in more situations with proper context sensitive suggestions
• Show instruction and label details in auto-complete prompts
• Show tooltip with details when hovering over instructions in the code
• Make the user input prompt more visible when an Input instruction is executed
• Improve text contrast in the status bar

Code changes:

• Update code to use Svelte 5 Runes (was previously written for Svelte 4)

[auroranil]

Do we want to version this PR?

[cyderize]

Do we want to version this PR?

Yes, I think so. I forgot to do that - I'll fix that later today