Write docs for API

[fremail]

Here is the full list of functions:

• [ ] createRoot
• [ ] fetchRoot
• [ ] fetchTree
• [ ] fetchRoots
• [ ] hasPrevSibling
• [ ] hasNextSibling
• [ ] hasChildren
• [ ] hasParent
• [ ] getPrevSibling
• [ ] getNextSibling
• [ ] getSiblings
• [ ] getFirstChild
• [ ] getLastChild
• [ ] getChildren
• [ ] getDescendants
• [ ] getParent
• [ ] getAncestors
• [ ] getNumberChildren
• [ ] getNumberDescendants
• [ ] insertAsParentOf
• [ ] insertAsPrevSiblingOf
• [ ] insertAsNextSiblingOf
• [ ] insertAsFirstChildOf
• [ ] insertAsLastChildOf
• [ ] moveAsPrevSiblingOf
• [ ] moveAsNextSiblingOf
• [ ] moveAsFirstChildOf
• [ ] moveAsLastChildOf
• [ ] makeRoot
• [ ] addChild
• [ ] isLeaf
• [ ] isRoot
• [ ] isEqualTo
• [ ] isDescendantOf
• [ ] isDescendantOfOrEqualTo
• [ ] isAncestorOf
• [ ] isValidNode
• [ ] detach
• [ ] delete

[fremail]

Added brief API docs to wiki. Will keep it open to add more detailed docs