Move Prop & Scripting related information

[towneh]

Related to recent PR: #88

This all went under the World section, which isn't accurate, better to move this to the Prop section. For the scripting guides, we can move these to a new section called Scripting.

[towneh]

Pushed 5284fec to setup separate Scripting section

[towneh]

Pushed 21a8425 to migrate existing Scripting docs

[towneh]

96186ea & e2b9d6a pushed to move Props guidance in to corresponding section.

[towneh]

@Chylum to be aware of this.

Also I removed the direct link to the Opticor package. Let's be mindful to only include content that has no Copyright files (or MIT only) when providing examples in the official documentation.