Remove mentions of design references

doc/user/markdown.md

@@ -408,7 +408,6 @@ GFM will recognize the following:
 | merge request                   | `!123`                     | `namespace/project!123`                 | `project!123`                  |
 | snippet                         | `$123`                     | `namespace/project$123`                 | `project$123`                  |
 | epic **(ULTIMATE)**             | `&123`                     | `group1/subgroup&123`                   |                                |
-| design **(PREMIUM)**            | `#123[file.jpg]` or `#123["file.png"]` | `group1/subgroup#123[file.png]`         | `project#123[file.png]`         |
 | label by ID                     | `~123`                     | `namespace/project~123`                 | `project~123`                  |
 | one-word label by name          | `~bug`                     | `namespace/project~bug`                 | `project~bug`                  |
 | multi-word label by name        | `~"feature request"`       | `namespace/project~"feature request"`   | `project~"feature request"`    |

doc/user/project/issues/design_management.md

@@ -39,13 +39,6 @@ Design Management requires that projects are using
 
 If the requirements are not met, the **Designs** tab displays a message to the user.
 
-### Feature Flags
-
-- Reference Parsing
-
-  Designs support short references in Markdown, but this needs to be enabled by setting
-  the `:design_management_reference_filter_gfm_pipeline` feature flag.
-
 ## Supported files
 
 Files uploaded must have a file extension of either `png`, `jpg`, `jpeg`,
@@ -53,7 +46,6 @@ Files uploaded must have a file extension of either `png`, `jpg`, `jpeg`,
 
 Support for [SVG files](https://gitlab.com/gitlab-org/gitlab/issues/12771)
 and [PDFs](https://gitlab.com/gitlab-org/gitlab/issues/32811) is planned for a future release.
-
 ## Limitations
 
 - Design uploads are limited to 10 files at a time.
@@ -169,32 +161,3 @@ Different discussions have different badge numbers:
 
 From GitLab 12.5 on, new annotations will be outputted to the issue activity,
 so that everyone involved can participate in the discussion.
-
-## References
-
-GitLab Flavored Markdown supports references to designs. The syntax for this is:
-
-  `#123[file.jpg]` - the issue reference, with the filename in square braces
-
-File names may contain a variety of odd characters, so two escaping mechanisms are supported:
-
-### Quoting
-
-File names may be quoted with double quotation marks, eg:
-
-  `#123["file.jpg"]`
-
-This is useful if, for instance, your filename has square braces in its name. In this scheme, all
-double quotation marks in the file name need to be escaped with backslashes, and backslashes need
-to be escaped likewise:
-
-  `#123["with with \"quote\" marks and a backslash \\.png"]`
-
-### Base64 Encoding
-
-In the case of file names that include HTML elements, you will need to escape these names to avoid
-them being processed as HTML literals. To do this, we support base64 encoding, eg.
-
-  The file `<a>.jpg` can be referenced as `#123[base64:PGE+LmpwZwo=]`
-
-Obviously we would advise against using such filenames.