improve documentation

Author: NullIsOne

Source/Collection/Modifier/CollectionCommonModifier.swift

@@ -87,6 +87,8 @@ class CollectionCommonModifier: Modifier<UICollectionView, CollectionItemAnimati
     ///
     /// - parameter indexDictionary: dictionary where **key** is new section index and value is location of items to insert
     /// - parameter insertAnimation: animation of insert operation
+    ///  - Warning: make sure that you do not have mistake in indexes inside `indexDictionary`.
+    ///  For example, if you are inserting **many sections** using this method you should notice that **index** cannot be greater than **final number of sections**.
     override func insertSectionsAndRows(at indexDictionary: [Int: [IndexPath]],
                                         with insertAnimation: CollectionItemAnimation?) {
         guard let view = view else { return }

Source/Protocols/Modifier/Modifier.swift

@@ -64,6 +64,8 @@ open class Modifier<View: UIView, Animation> {
     ///
     /// - parameter indexDictionary: dictionary where **key** is new section index and value is location of subviews to insert
     /// - parameter insertAnimation: animation of insert operation
+    ///  - Warning: make sure that you do not have mistake in indexes inside `indexDictionary`.
+    ///  For example, if you are inserting **many sections** using this method you should notice that **index** cannot be greater than **final number of sections**.
     open func insertSectionsAndRows(at indexDictionary: [Int: [IndexPath]], with insertAnimation: Animation?) {
         preconditionFailure("\(#function) must be overriden in child")
     }

Source/Table/Modifier/TableCommonModifier.swift

@@ -87,6 +87,8 @@ class TableCommonModifier: Modifier<UITableView, UITableView.RowAnimation> {
     ///
     /// - parameter indexDictionary: dictionary where **key** is new section index and value is location of subviews to insert
     /// - parameter insertAnimation: animation of insert operation
+    ///  - Warning: make sure that you do not have mistake in indexes inside `indexDictionary`.
+    ///  For example, if you are inserting **many sections** using this method you should notice that **index** cannot be greater than **final number of sections**.
     override func insertSectionsAndRows(at indexDictionary: [Int: [IndexPath]],
                                         with insertAnimation: UITableView.RowAnimation?) {
         guard let view = view else { return }
@@ -95,7 +97,6 @@ class TableCommonModifier: Modifier<UITableView, UITableView.RowAnimation> {
             let allValues = indexDictionary.values.flatMap { $0 }
             view?.insertSections(setOfKeys, with: insertAnimation ?? .none)
             view?.insertRows(at: allValues, with: insertAnimation ?? .none)
-
         }
     }