Add @param, @return in the code base for the editor module

tested on 8.0.x and 8.1.x-dev.
It works on both and looks ok.

+++ b/core/modules/editor/js/editor.formattedTextEditor.js
@@ -94,8 +94,7 @@
-      var to = state;
-      switch (to) {
+      switch (state) {

Sorry, I forgot to mention it also on quickedit modules. We may have to change them all to keep consistent code in those files.

1. +++ b/core/modules/editor/js/editor.formattedTextEditor.js
   @@ -94,8 +94,7 @@
   -      var to = state;
   -      switch (to) {
   +      switch (state) {
   

   No. Please don't change this. This variable is intentionally there, for legibility.

2. +++ b/core/modules/editor/src/Element.php
   @@ -36,6 +36,12 @@ public function __construct(PluginManagerInterface $plugin_manager) {
   +   * @param array $element
   +   *   An array of elements.
   +   *
   +   * @return array
   +   *   An pre rendered text format of array.
   

   We don't do this for #pre_render callbacks.

3. +++ b/core/modules/editor/src/Plugin/InPlaceEditor/Editor.php
   @@ -59,6 +59,12 @@ function getMetadata(FieldItemListInterface $items) {
   +   *   A format id.
   

   s/format/text format/

4. +++ b/core/modules/editor/src/Plugin/InPlaceEditor/Editor.php
   @@ -59,6 +59,12 @@ function getMetadata(FieldItemListInterface $items) {
   +   * @return bool
   +   *   A bool value.
   

   LOL.

   Omit the second line, please. The single-line explanation at the top of this docblock already covers this.

5. +++ b/core/modules/editor/src/Tests/QuickEditIntegrationTest.php
   @@ -112,6 +112,16 @@ protected function setUp() {
   +   *   An integer id.
   

   LOL. Needs to be fixed. This is useless.

6. +++ b/core/modules/editor/src/Tests/QuickEditIntegrationTest.php
   @@ -112,6 +112,16 @@ protected function setUp() {
   +   *   Returns a selected editor.
   

   Inaccurate.

Did the changes pointed by @Wim Leers at #5, in addition to s/id/ID/ and:

    * @param int $entity_id
-   *   An integer id.
+   *   An entity ID.

Just two more nits, then this is RTBC:

1. +++ b/core/modules/editor/src/Tests/QuickEditIntegrationTest.php
   @@ -112,6 +112,16 @@ protected function setUp() {
       * Returns the in-place editor that Edit selects.
   

   Returns the in-place editor that quickedit selects.

2. +++ b/core/modules/editor/src/Tests/QuickEditIntegrationTest.php
   @@ -112,6 +112,16 @@ protected function setUp() {
   +   *   Returns a selected editor.
   

   Returns the selected in-place editor.

Afaics there is one missing... function editor_load($format_id) { every other function is either a hook or callback which don't need documentation.

Committed 102928a and pushed to 8.0.x. Thanks!