Update "Transformation Overview" chapter (#926)

- Most transformations no longer exist.

Documentation/ApiOverview/Rte/Transformations/Overview.rst

@@ -45,63 +45,17 @@ Transformation Filters
 
 .. ### BEGIN~OF~TABLE ###
 
-.. container:: table-row
-
-   Transformation filter
-         ts\_transform
-
-   Description
-         Transforms the content with regard to most of the issues related to
-         content elements types 'Text' and 'Text & Images'. The mode is
-         optimized for the content rendering of the static template "content
-         (default)" which uses old :code:`<font>` tag style rendering.
-
-         The mode is a "hybrid" mode which tries to save only the necessary HTML in the
-         database so that content might still be easily edited without the RTE.
-         For instance a text paragraph will be encapsulated in :code:`<p>` tags while
-         in the database it will just be a single line ended by a line break
-         character.
-
-         .. tip::
-
-            This transformation produces rather old style output and you should avoid it.
-
-
 .. container:: table-row
 
    Transformation filter
          css\_transform
 
    Description
-         Like "ts\_transform", but producing a modern markup.
-
-         This mode is optimized for the content rendering done by "css\_styled\_content".
-
-
-.. container:: table-row
-
-   Transformation filter
-         ts\_preserve
-
-   Description
-         Converts the list of preserved tags - if any - to :code:`<span>` tags with a
-         custom parameter 'specialtag' which holds the value of the original
-         tag.
-
-         **Deprecated**
-
-
-.. container:: table-row
-
-   Transformation filter
-         ts\_images
-
-   Description
-         Checks if any images on the page is from external URLs and if so they
-         are fetched and stored in the uploads/ folder. In addition 'magic'
-         images are evaluated to see if their size has changed and if so the
-         image is recalculated on the server. Finally absolute URLs are
-         converted to relative URLs for all local images.
+         Transforms the html markup either for display in the richtext editor or for saving in the db. 
+         The name "css_transform" is historical; earlier TYPO3 versions had a long since removed 
+         "ts_transform" mode, which basically only saved a minimum amount of HTML in the db and 
+         produced a lot of nowadays outdated markup like :code:`<font>` tag style rendering in the 
+         frontend. 
 
 
 .. container:: table-row
@@ -110,45 +64,14 @@ Transformation Filters
          ts\_links
 
    Description
-         Converts the absolute URLs of links to the TypoScript specific
-         <LINK>-tag. This process is designed to make links in concordance with
-         the typolink function in the TypoScript frontend.
-
+         Processes anchor tags and resolves them via :code:`\TYPO3\CMS\Core\LinkHandling\LinkService`
+         before saving them to the db, while using the TYPO3-internal t3:// syntax.
+
 .. ###### END~OF~TABLE ######
 
 
 .. _transformations-overview-meta:
 
-Meta Transformations
-====================
-
-Meta transformations are special modes that include several filters.
-
-
-.. ### BEGIN~OF~TABLE ###
-
-.. container:: table-row
-
-   Transformation filter
-         ts
-
-   Description
-         Includes the following filters: "ts\_transform", "ts\_preserve", "ts\_images",
-         "ts\_links". **Obsolete**.
-
-
-.. container:: table-row
-
-   Transformation filter
-         ts\_css
-
-   Description
-         Includes the following filters: "css\_transform", "ts\_images", "ts\_links".
-         Recommended transformation. Use this for your RTE-enables fields and you
-         should be safe.
-
-.. ###### END~OF~TABLE ######
-
 
 In addition, it is possible to define :ref:`custom transformations <transformations-custom>`
 can be created allowing your to add your own tailor made transformations with a PHP class where you