Update ORG-NEWS

* etc/ORG-NEWS: Add summary of `org-latex-preview' changes.

etc/ORG-NEWS

@@ -569,6 +569,155 @@ constant.
 If you still want to use python-mode with ob-python, you might
 consider [[https://gitlab.com/jackkamm/ob-python-mode-mode][ob-python-mode-mode]], where the code to support python-mode
 has been ported to.
+*** The LaTeX preview system has been overhauled
+
+Org's LaTeX preview system has been overhauled
+
+
+Org mode's LaTeX preview system has been rewritten with several improvements and new features.
+
+- LaTeX Previews are generated in bulk, and hundreds of LaTeX fragments can be processed per second.
+- Images are placed in the buffer continuously as they are generated.
+- Preview generation is asynchronous and will not block Emacs.
+- Inline previews are aligned and scaled to match the font baseline and size.
+- Previews scale along with text when the text scale is changed.
+- Previews are coloured to match surrounding text and the active theme.
+- SVG previews automatically change colors when the active theme changes.
+- Error encountered when compiling LaTeX fragments can be accessed by mousing over preview images.
+- Preview overlays can hide and show themselves dynamically based on cursor position.
+- Org mode can auto-generate LaTeX previews as you type or edit the text of existing ones.
+- Org mode can keep equation numbering consistent by regenerating previews as needed.
+
+**** New features
+
+***** New minor mode ~org-latex-preview-auto-mode~
+
+When this mode is turned on, LaTeX preview overlays in the buffer can be temporarily disabled by moving the cursor into them.  Moving the cursor out will display the LaTeX preview image overlay again.  Additionally, editing LaTeX fragments that have previews will cause the preview images to be updated.
+
+If the option ~org-latex-preview-auto-generate~ is non-nil (which see), previews for LaTeX fragments will be auto-generated as you type.
+
+
+**** New options
+
+***** A new option ~org-latex-preview-compiler-command-map~ for setting precompile commands
+
+This alist maps compilers in ~org-latex-compilers~ to command strings
+used for LaTeX precompilation when creating previews or LaTeX exports.
+
+***** New option ~org-latex-preview-persist~ to enable preview image caching
+
+When non-nil, images produced using ~org-latex-preview~ will be cached and
+persisted across Emacs sessions using ~org-persist~.
+
+***** New option ~org-latex-preview-persist-expiry~ to set persistence period
+
+This is the number of days for which LaTeX preview images will be
+cached, assuming persistence is turned on with
+~org-latex-preview-persist~.
+
+***** New option ~org-latex-preview-processing-indicator~ to indicate preview processing for LaTeX fragments
+
+This option controls the style of visual indicator for LaTeX fragments
+currently being processed.
+
+***** New option ~org-latex-preview-numbered~ to automatically renumber previewed LaTeX environments
+
+When non-nil, previewed LaTeX environments in the buffer are
+renumbered automatically as required.
+
+***** New option ~org-latex-preview-width~ to control the text width for LaTeX fragment previews
+
+This option controls the width of text in preview images.  This is
+relevant for displaymath-type LaTeX environments, and can be specified
+in multiple ways.
+
+***** New option ~org-latex-preview-use-precompilation~ to control LaTeX precompilation
+
+This option controls whether LaTeX headers for buffers are precompiled
+when generating the first preview for the buffer.  Precompilation can
+speed up preview generation by a moderate to large amount depending on
+the complexity of the header.
+
+***** New option ~org-latex-preview-auto-generate~ to auto-generate LaTeX previews when typing
+
+When using ~org-latex-preview-auto-mode~ (which see), setting this option to a non-nil value will cause LaTeX previews to be rendered as you type LaTeX fragments.  This works however new text is added to the buffer, for example by yanking.  When this option is nil and ~org-latex-preview-auto-mode~ is on, existing previews for LaTeX fragments will still be auto-regenerated when edited but no new ones will be auto-generated.
+
+**** Removed or renamed functions and variables
+
+***** Mark ~org-format-latex-options~ obsolete
+
+Use ~org-latex-preview-options~ instead.  The replacement acts in the
+same way, except that
+- the preview image render size and display size can be independently
+  controlled with the =:scale= and =:zoom= plist keys, and
+- the HTML export-specific parameters =:html-scale=,
+  =:html-foreground= and =:html-background= have been
+moved to ~org-html-latex-image-options~, which see.
+
+***** Mark ~org-format-latex-header~ obsolete
+
+Use ~org-latex-preview-header~ instead.  The replacement variable
+behaves the exact same way and is renamed for consistency.
+
+***** Mark ~org-preview-latex-default-process~ obsolete
+
+Use ~org-latex-preview-default-process~ instead.  The replacement
+variable behaves the exact same way and is renamed for consistency.
+
+***** Mark ~org-preview-latex-process-alist~ obsolete
+
+Use ~org-latex-preview-process-alist~ instead.  The replacement
+variable acts in the same way, except that =:latex-compiler= must now
+be a single command or a list containing a single command.  The
+placeholder ="%S"= in the format string for =:latex-compiler= is
+ignored.
+
+***** Mark ~org-clear-latex-preview~ obsolete
+
+Use ~org-latex-preview-clear-overlays~ instead.  The replacement
+function acts in the exact same way and is renamed for consistency.
+
+***** Mark ~org-place-formula-image~ obsolete
+
+This functionality is replaced with ~org-latex-preview-place-image~
+(for images) and ~org-latex-preview-place-image-link~ (for links).
+
+***** Mark ~org-latex-color-format~ obsolete
+
+Use ~org-latex-preview--format-color~ instead.  The replacement
+function acts in the exact same way and is renamed for consistency.
+
+***** Mark ~org-latex-color~ obsolete
+
+Use ~org-latex-preview--attr-color~ instead.  The replacement function
+acts in the exact same way and is renamed for consistency.
+
+***** Mark ~org-normalize-color~ obsolete
+
+Use ~org-latex-preview--normalize-color~ instead.  The replacement
+function acts in the exact same way and is renamed for consistency.
+
+***** Mark ~org-latex-to-mathml-jar-file~ obsolete
+
+Use ~org-mathml-converter-jar-file~ instead.  The replacement variable
+acts in the exact same way and is renamed for consistency.
+
+***** Mark ~org-latex-to-mathml-convert-command~ obsolete
+
+Use ~org-mathml-convert-command~ instead.  The replacement variable
+acts in the exact same way and is renamed for consistency.
+
+***** Mark ~org-format-latex-mathml-available-p~ obsolete
+
+Use ~org-mathml-converter-available-p~ instead.  The replacement
+function acts in the exact same way and is renamed for consistency.
+
+***** Mark ~org-create-math-formula~ obsolete
+
+Use ~org-mathml-convert-latex~ instead.  The replacement function acts
+in the exact same way and is renamed for consistency.
+
+
 
 *** =ox-icalendar.el= line ending fix may affect downstream packages