add release notes for #8084

CHANGELOG.txt

@@ -16,6 +16,7 @@ Changelog
  * Remove IE11 warnings (Gianluca De Cola)
  * Remove the legacy Hallo rich text editor as it has moved to an external package (LB (Ben Johnston))
  * Increase the size of checkboxes throughout the UI, and simplify their alignment (Steven Steinwand)
+ * Adopt [MyST](https://myst-parser.readthedocs.io/en/latest/) for parsing documentation written in Markdown, replaces recommonmark (LB (Ben Johnston), Thibaud Colas)
  * Fix: When using `simple_translations` ensure that the user is redirected to the page edit view when submitting for a single locale (Mitchel Cabuloy)
  * Fix: When previewing unsaved changes to `Form` pages, ensure that all added fields are correctly shown in the preview (Joshua Munn)
  * Fix: When Documents (e.g. PDFs) have been configured to be served inline via `WAGTAILDOCS_CONTENT_TYPES` & `WAGTAILDOCS_INLINE_CONTENT_TYPES` ensure that the filename is correctly set in the `Content-Disposition` header so that saving the files will use the correct filename (John-Scott Atlakson)

docs/releases/2.17.md

@@ -36,6 +36,7 @@ The panel types `StreamFieldPanel`, `RichTextFieldPanel`, `ImageChooserPanel`, `
  * Replace `data_json` `TextField` with `data` `JSONField` in `BaseLogEntry` (Sage Abdullah)
  * Remove the legacy Hallo rich text editor as it has moved to an external package (LB (Ben Johnston))
  * Increase the size of checkboxes throughout the UI, and simplify their alignment (Steven Steinwand)
+ * Adopt [MyST](https://myst-parser.readthedocs.io/en/latest/) for parsing documentation written in Markdown, replaces recommonmark (LB (Ben Johnston), Thibaud Colas)
 
 
 ### Bug fixes