Adds Config for Highlighted Mould color

[zmanowar]

I had trouble noticing the default green.

• Updates runeliteVersion to latest.release, inline with the example plugin repo.
• Adds a config item mouldHighlightColor
• Uses config.mouldHighlightColor when highlighting the mould.

I initially started to implement full-widget highlighting but there were a few issues I wasn't confident were elegantly solved. (highlight-widgets branch) -- happy to work through full widget highlighting if you prefer!

Full highlight example

 Blue highlight is the bestWidget from the MouldHelper and the other is the normal selected highlight, just for comparison.

[pwatts6060]

Hi, thanks for your efforts. This will be added among other color highlights in another PR I just made. When it's updated there will be a section called Colour at the bottom of the plugin config for customizing almost all of the colours used in the plugin.