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