[clang-format] [NFC] add recent changes to release notes

Summary: clang-tidy keeps nice release notes of what is added, have clang-format do the same.

Reviewers: klimek, mitchell-stellar, sylvestre.ledru, sammccall

Reviewed By: mitchell-stellar

Subscribers: merge_guards_bot, Eugene.Zelenko, cfe-commits

Tags: #clang-format, #clang

Differential Revision: https://reviews.llvm.org/D70355

clang/docs/ReleaseNotes.rst

@@ -138,9 +138,6 @@ Windows Support
 
     error LNK2005: "bool const std::_Is_integral<int>" (??$_Is_integral@H@std@@3_NB) already defined
 
-
-
-
 C Language Changes in Clang
 ---------------------------
 
@@ -296,13 +293,16 @@ clang-format
   - ``Auto`` is the default and detects style from the code (this is unchanged).
 
   The previous values of ``Cpp03`` and ``Cpp11`` are deprecated. Note that
-  ``Cpp11`` is treated as ``Latest``, as this was always clang-format's behavior.
-  (One motivation for this change is the new name describes the behavior better).
+  ``Cpp11`` is treated as ``Latest``, as this was always clang-format's
+  behavior. (One motivation for this change is the new name describes the
+  behavior better).
 
-- clang-format gets a new option called ``--dry-run`` or ``-n`` to emit a
-  warning.
+- Clang-format has a new option called ``--dry-run`` or ``-n`` to emit a
+  warning for clang-format violations. This can be used together
+  with --ferror-limit=N to limit the number of warnings per file and --Werror
+  to make warnings into errors.
 
-- Option *IncludeIsMainSourceRegex* added to allow for additional
+- Option *IncludeIsMainSourceRegex* has been added to allow for additional
   suffixes and file extensions to be considered as a source file
   for execution of logic that looks for "main *include* file" to put
   it on top.
@@ -320,12 +320,31 @@ clang-format
   ``ClassImpl.hpp`` would not have the main include file put on top
   before any other include.
 
+- Options ``DeriveLineEnding`` and  ``UseCRLF`` have been added to allow
+  clang-format to control the newlines. ``DeriveLineEnding`` is by default
+  ``true`` and reflects is the existing mechanism, which based is on majority
+  rule. The new options allows this to be turned off and ``UseCRLF`` to control
+  the decision as to which sort of line ending to use.
+
+- Option ``SpaceBeforeSquareBrackets`` has been added to insert a space before
+  array declarations.
+
+  .. code-block:: c++
+
+    int a [5];    vs    int a[5];
+
+- Clang-format now supports JavaScript null operators.
+
+  .. code-block:: c++
+
+    const x = foo ?? default;
+    const z = foo?.bar?.baz;
+
 libclang
 --------
 
 - ...
 
-
 Static Analyzer
 ---------------
 
@@ -373,7 +392,6 @@ Undefined Behavior Sanitizer (UBSan)
         return getelementpointer_inbounds(base, offset);
       }
 
-
 Core Analysis Improvements
 ==========================