types: fix type definitions (#284)

postcss-selector-parser.d.ts

@@ -166,7 +166,7 @@ declare namespace parser {
         replaceWith(...nodes: Node[]): Node;
         next(): Node;
         prev(): Node;
-        clone(opts?: {[override: string]:any}): Node;
+        clone(opts?: {[override: string]:any}): this;
         /**
          * Return whether this node includes the character at the position of the given line and column.
          * Returns undefined if the nodes lack sufficient source metadata to determine the position.
@@ -211,8 +211,8 @@ declare namespace parser {
         Child extends Node = Node
     > extends Base<Value> {
         nodes: Array<Child>;
-        append(selector: Selector): this;
-        prepend(selector: Selector): this;
+        append(selector: Child): this;
+        prepend(selector: Child): this;
         at(index: number): Child;
         /**
          * Return the most specific node at the line and column number given.
@@ -233,8 +233,8 @@ declare namespace parser {
         readonly last: Child;
         readonly length: number;
         removeChild(child: Child): this;
-        removeAll(): Container;
-        empty(): Container;
+        removeAll(): this;
+        empty(): this;
         insertAfter(oldNode: Child, newNode: Child): this;
         insertBefore(oldNode: Child, newNode: Child): this;
         each(callback: (node: Child) => boolean | void): boolean | undefined;