docs: add JSDoc for all library exports

src/BaseRouter.tsx

@@ -1,6 +1,10 @@
 import shortid from 'shortid';
 import { CommonAction, NavigationState } from './types';
 
+/**
+ * Base router object that can be used when writing custom routers.
+ * This provides few helper methods to handle common actions such as `RESET`.
+ */
 const BaseRouter = {
   getStateForAction<State extends NavigationState>(
     state: State,

src/NavigationContainer.tsx

@@ -69,7 +69,16 @@ const getPartialState = (
   };
 };
 
-function NavigationContainer(
+/**
+ * Container component which holds the navigation state.
+ * This should be rendered at the root wrapping the whole app.
+ *
+ * @param props.initialState Initial state object for the navigation tree.
+ * @param props.onStateChange Callback which is called with the latest navigation state when it changes.
+ * @param props.children Child elements to render the content.
+ * @param props.ref Ref object which refers to the navigation object containing helper methods.
+ */
+const Container = React.forwardRef(function NavigationContainer(
   { initialState, onStateChange, children }: Props,
   ref: React.Ref<NavigationHelpers<ParamListBase>>
 ) {
@@ -185,6 +194,6 @@ function NavigationContainer(
       </NavigationBuilderContext.Provider>
     </NavigationStateContext.Provider>
   );
-}
+});
 
-export default React.forwardRef(NavigationContainer);
+export default Container;

src/createNavigator.tsx

@@ -2,17 +2,24 @@ import * as React from 'react';
 import Screen from './Screen';
 import { ParamListBase, RouteConfig, TypedNavigator } from './types';
 
+/**
+ * Higher order component to create a `Navigator` and `Screen` pair.
+ * Custom navigators should wrap the navigator component in `createNavigator` before exporting.
+ *
+ * @param NavigatorComponent The navigtor component to wrap.
+ * @returns Factory method to create a `Navigator` and `Screen` pair.
+ */
 export default function createNavigator<
   ScreenOptions extends object,
   N extends React.ComponentType<any>
->(RawNavigator: N) {
-  return function Navigator<ParamList extends ParamListBase>(): TypedNavigator<
+>(NavigatorComponent: N) {
+  return <ParamList extends ParamListBase>(): TypedNavigator<
     ParamList,
     ScreenOptions,
-    typeof RawNavigator
-  > {
+    typeof NavigatorComponent
+  > => {
     return {
-      Navigator: RawNavigator,
+      Navigator: NavigatorComponent,
       Screen: Screen as React.ComponentType<
         RouteConfig<ParamList, keyof ParamList, ScreenOptions>
       >,

src/useFocusEffect.tsx

@@ -3,6 +3,13 @@ import useNavigation from './useNavigation';
 
 type EffectCallback = (() => undefined) | (() => () => void);
 
+/**
+ * Hook to an effect in a focused screen, similar to `React.useEffect`.
+ * This can be used to perform side-effects such as fetching data or subscribing to events.
+ * The passed callback should be wrapped in `React.useCallback` to avoid running the effect too often.
+ *
+ * @param callback Memoized callback containing the effect, should optionally return a cleanup function.
+ */
 export default function useFocusEffect(callback: EffectCallback) {
   const navigation = useNavigation();
 

src/useNavigation.tsx

@@ -2,6 +2,11 @@ import * as React from 'react';
 import NavigationContext from './NavigationContext';
 import { NavigationProp, ParamListBase } from './types';
 
+/**
+ * Hook to access the navigation prop of the parent screen anywhere.
+ *
+ * @returns Navigation prop of the parent screen.
+ */
 export default function useNavigation<
   T extends NavigationProp<ParamListBase>
 >(): T {

src/useNavigationBuilder.tsx

@@ -57,6 +57,13 @@ const getRouteConfigsFromChildren = <ScreenOptions extends object>(
     );
   }, []);
 
+/**
+ * Hook for building navigators.
+ *
+ * @param createRouter Factory method which returns router object.
+ * @param options Options object containing `children` and additional options for the router.
+ * @returns An object containing `state`, `navigation`, `descriptors` objects.
+ */
 export default function useNavigationBuilder<
   State extends NavigationState,
   ScreenOptions extends object,