Improving Javadoc of flattenAsFlowable and flattenAsObservable methods (#6276) (#6408)

Author: thiyagu-7

src/main/java/io/reactivex/Maybe.java

@@ -3062,8 +3062,8 @@ public final <U, R> Maybe<R> flatMap(Function<? super T, ? extends MaybeSource<?
     }
 
     /**
-     * Returns a Flowable that merges each item emitted by the source Maybe with the values in an
-     * Iterable corresponding to that item that is generated by a selector.
+     * Maps the success value of the upstream {@link Maybe} into an {@link Iterable} and emits its items as a
+     * {@link Flowable} sequence.
      * <p>
      * <img width="640" height="373" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/flattenAsFlowable.png" alt="">
      * <dl>
@@ -3091,7 +3091,8 @@ public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? exten
     }
 
     /**
-     * Returns an Observable that maps a success value into an Iterable and emits its items.
+     * Maps the success value of the upstream {@link Maybe} into an {@link Iterable} and emits its items as an
+     * {@link Observable} sequence.
      * <p>
      * <img width="640" height="373" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/flattenAsObservable.png" alt="">
      * <dl>

src/main/java/io/reactivex/Single.java

@@ -2711,8 +2711,8 @@ public final <R> Flowable<R> flatMapPublisher(Function<? super T, ? extends Publ
     }
 
     /**
-     * Returns a Flowable that merges each item emitted by the source Single with the values in an
-     * Iterable corresponding to that item that is generated by a selector.
+     * Maps the success value of the upstream {@link Single} into an {@link Iterable} and emits its items as a
+     * {@link Flowable} sequence.
      * <p>
      * <img width="640" height="373" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/flattenAsFlowable.png" alt="">
      * <dl>
@@ -2740,7 +2740,8 @@ public final <U> Flowable<U> flattenAsFlowable(final Function<? super T, ? exten
     }
 
     /**
-     * Returns an Observable that maps a success value into an Iterable and emits its items.
+     * Maps the success value of the upstream {@link Single} into an {@link Iterable} and emits its items as an
+     * {@link Observable} sequence.
      * <p>
      * <img width="640" height="373" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/flattenAsObservable.png" alt="">
      * <dl>