Merge Source.apply and Source.from docs (#606)

akka-docs/src/main/paradox/.htaccess

@@ -16,9 +16,10 @@ RedirectMatch 301 ^(.*)/stream/stages-overview\.html$ $1/stream/operators/index.
 RedirectMatch 301 ^(.*)/agents\.html$ $1/project/migration-guide-2.5.x-2.6.x.html
 RedirectMatch 301 ^(.*)/typed-actors\.html$ $1/project/migration-guide-2.5.x-2.6.x.html#typedactor
 
-
 RedirectMatch 301 ^(.*)/stream/operators/Source-or-Flow/balance\.html$ $1/stream/operators/Balance.html
 RedirectMatch 301 ^(.*)/stream/operators/Source-or-Flow/broadcast\.html$ $1/stream/operators/Broadcast.html
 RedirectMatch 301 ^(.*)/stream/operators/Source-or-Flow/partition\.html$ $1/stream/operators/Partition.html
 RedirectMatch 301 ^(.*)/stream/operators/Source-or-Flow/unzip\.html$ $1/stream/operators/unzip.html
 RedirectMatch 301 ^(.*)/stream/operators/Source-or-Flow/UnzipWith\.html$ $1/stream/operators/UnzipWith.html
+
+RedirectMatch 301 ^(.*)/stream/operators/Source-or-Flow/apply\.html$ $1/stream/operators/Source/from.html

akka-docs/src/main/paradox/stream/operators/Source-or-Flow/apply.md

@@ -1,24 +0,0 @@
-# apply
-
-Stream the values of an `immutable.Seq`.
-
-@ref[Source operators](../index.md#source-operators)
-
-@@@ div { .group-scala }
-## Signature
-
-@@signature [Source.scala](/akka-stream/src/main/scala/akka/stream/scaladsl/Source.scala) { #apply }
-@@@
-
-## Description
-
-Stream the values of an `immutable.Seq`.
-
-@@@div { .callout }
-
-**emits** the next value of the seq
-
-**completes** when the last element of the seq has been emitted
-
-@@@
-

akka-docs/src/main/paradox/stream/operators/Source/from.md

@@ -1,6 +1,6 @@
-# from
+# @scala[apply]@java[from]
 
-Stream the values of an `Iterable`.
+Stream the values of an @scala[`immutable.Seq`]@java[`Iterable`].
 
 @ref[Source operators](../index.md#source-operators)
 
@@ -9,14 +9,14 @@ Stream the values of an `Iterable`.
 
 ## Signature
 
-@@signature [Source.scala](/akka-stream/src/main/scala/akka/stream/javadsl/Source.scala) { #from }
+@@signature [Source.scala](/akka-stream/src/main/scala/akka/stream/scaladsl/Source.scala) { #apply }
 
 @@@
 
 ## Description
 
-Stream the values of an `Iterable`. Make sure the `Iterable` is immutable or at least not modified after being used
-as a source. Otherwise the stream may fail with `ConcurrentModificationException` or other more subtle errors may occur.
+Stream the values of an @scala[`immutable.Seq`]@java[`Iterable`]. @java[Make sure the `Iterable` is immutable or at least not modified after being used
+as a source. Otherwise the stream may fail with `ConcurrentModificationException` or other more subtle errors may occur.]
 
 @@@div { .callout }
 

akka-docs/src/main/paradox/stream/operators/index.md

@@ -16,7 +16,7 @@ These built-in sources are available from @scala[`akka.stream.scaladsl.Source`]
 |Source|<a name="cycle"></a>@ref[cycle](Source/cycle.md)|Stream iterator in cycled manner.|
 |Source|<a name="empty"></a>@ref[empty](Source/empty.md)|Complete right away without ever emitting any elements.|
 |Source|<a name="failed"></a>@ref[failed](Source/failed.md)|Fail directly with a user specified exception.|
-|Source|<a name="from"></a>@ref[from](Source/from.md)|Stream the values of an `Iterable`.|
+|Source|<a name="from"></a>@ref[@scala[apply]@java[from]](Source/from.md)|Stream the values of an @scala[`immutable.Seq`]@java[`Iterable`].|
 |Source|<a name="fromcompletionstage"></a>@ref[fromCompletionStage](Source/fromCompletionStage.md)|Send the single value of the `CompletionStage` when it completes and there is demand.|
 |Source|<a name="fromfuture"></a>@ref[fromFuture](Source/fromFuture.md)|Send the single value of the `Future` when it completes and there is demand.|
 |Source|<a name="fromfuturesource"></a>@ref[fromFutureSource](Source/fromFutureSource.md)|Streams the elements of the given future source once it successfully completes.|
@@ -334,7 +334,7 @@ For more background see the @ref[Error Handling in Streams](../stream-error.md)
 * [queue](Source/queue.md)
 * [unfoldResource](Source/unfoldResource.md)
 * [unfoldResourceAsync](Source/unfoldResourceAsync.md)
-* [from](Source/from.md)
+* [@scala[apply]@java[from]](Source/from.md)
 * [range](Source/range.md)
 * [concat](Source-or-Flow/concat.md)
 * [prepend](Source-or-Flow/prepend.md)

project/StreamOperatorsIndexGenerator.scala

@@ -202,7 +202,9 @@ object StreamOperatorsIndexGenerator extends AutoPlugin {
           lines
             .map(_._2)
             .sortBy(_._2)
-            .map { case (element, method, md, description) => s"""|$element|<a name="${method.toLowerCase}"></a>@ref[$method]($md)|$description|""" }
+            .map { case (element, method, md, description) =>
+              s"""|$element|<a name="${method.toLowerCase}"></a>@ref[${methodToShow(method)}]($md)|$description|"""
+            }
             .mkString("\n")
       )
 
@@ -217,12 +219,17 @@ object StreamOperatorsIndexGenerator extends AutoPlugin {
       "# Operators\n\n" +
         tables +
         "\n\n@@@ index\n\n" +
-        groupedDefs.map { case (_, method, md) => s"* [$method]($md)" }.mkString("\n") + "\n\n@@@\n"
+        groupedDefs.map { case (_, method, md) => s"* [${methodToShow(method)}]($md)" }.mkString("\n") + "\n\n@@@\n"
 
     if (!file.exists || IO.read(file) != content) IO.write(file, content)
     Seq(file)
   }
 
+  def methodToShow(method: String): String = method match {
+    case "from" => "@scala[apply]@java[from]"
+    case other => other
+  }
+
   def getDetails(file: File): (String, String) = try {
     val contents = IO.read(file)
     val lines = contents.split("\\r?\\n")