Update documentation format guide

Author: javiereguiluz

contributing/documentation/format.rst

@@ -2,19 +2,17 @@ Documentation Format
 ====================
 
 The Symfony documentation uses `reStructuredText`_ as its markup language and
-`Sphinx`_ for generating the documentation in the formats read by the end users,
-such as HTML and PDF.
+a custom tool called `Docs Builder`_ for generating the documentation pages.
 
 reStructuredText
 ----------------
 
 reStructuredText is a plain text markup syntax similar to Markdown, but much
-stricter with its syntax. If you are new to reStructuredText, take some time to
-familiarize with this format by reading the existing `Symfony documentation`_
-source code.
+stricter with its syntax. If you are new to reStructuredText, check out the
+`reStructuredText Primer`_ tutorial and the `reStructuredText Reference`_.
 
-If you want to learn more about this format, check out the `reStructuredText Primer`_
-tutorial and the `reStructuredText Reference`_.
+You can also take some time to familiarize with this format by reading the
+existing `Symfony documentation`_ source.
 
 .. warning::
 
@@ -24,12 +22,11 @@ tutorial and the `reStructuredText Reference`_.
     * Lists start at the beginning of a line (no indentation is allowed);
     * Inline code blocks use double-ticks (````like this````).
 
-Sphinx
-------
+Custom reStructuredText Directives
+----------------------------------
 
-Sphinx_ is a build system that provides tools to create documentation from
-reStructuredText documents. As such, it adds new directives and interpreted text
-roles to the standard reStructuredText markup. Read more about the `Sphinx Markup Constructs`_.
+The Symfony documentation includes several custom directives that extend the
+standard reStructuredText syntax.
 
 Syntax Highlighting
 ~~~~~~~~~~~~~~~~~~~
@@ -45,9 +42,9 @@ change it with the ``code-block`` directive:
 
 .. note::
 
-    Besides all of the major programming languages, the syntax highlighter
-    supports all kinds of markup and configuration languages. Check out the
-    list of `supported languages`_ on the syntax highlighter website.
+    Code highlighting is supported for all programming languages commonly used
+    in Symfony Docs, such as ``yaml``, ``xml``, ``twig``, ``html``, ``js``,
+    ``json``, ``text``, ``bash``, ``diff``, etc.
 
 .. _docs-configuration-blocks:
 
@@ -280,10 +277,8 @@ for Symfony versions that have a lower major version will be removed. For
 example, if Symfony 6.0 were released today, 5.0 to 5.4 ``versionadded`` and
 ``deprecated`` tags would be removed from the new ``6.0`` branch.
 
-.. _reStructuredText: https://docutils.sourceforge.io/rst.html
-.. _Sphinx: https://www.sphinx-doc.org/
+.. _`reStructuredText`: https://docutils.sourceforge.io/rst.html
+.. _`Docs Builder`: https://github.com/symfony-tools/docs-builder
 .. _`Symfony documentation`: https://github.com/symfony/symfony-docs
 .. _`reStructuredText Primer`: https://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html
 .. _`reStructuredText Reference`: https://docutils.sourceforge.io/docs/user/rst/quickref.html
-.. _`Sphinx Markup Constructs`: https://www.sphinx-doc.org/en/1.7/markup/index.html
-.. _`supported languages`: https://pygments.org/languages/