Changelog: added

- Converts GitLab Flavored Markdown Examples from old
  Golden Master approach to new approach.

- Adds numbering, table of contents, and other
  structure/styling to markdown examples, like the standard
  CommonMark and GitHub Flavored Markdown rendered HTML
  specifications

MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/101413

- Split examples into two files as documented in
  https://gitlab.com/gitlab-org/gitlab/-/merge_requests/98493

- Rename intro.txt to intro.md
- Rename ghfm_spec_v_0.29.txt to ghfm_spec_v_0.29.txt.md

- Validate that manually-curated config files
  do not have any invalid example names
- Also fixes some issues where yarn
  integrity check started failing on CI,
  possibly for reasons unrelated to this MR
- Also removes an unnecessary writable
  File.open that was overlooked in a
  previous refactor.

Remove unnecessary space from GLFM documentation

Add specs and generate example snapshots
for GitLab Flavored Markdown table of
contents

- Extract common fixture setup to new shared context
- Move shared contexts to common glfm directory
- Renaming files for consistency
- Clean up and improve some file reading and
  other logic

MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/96325

- These are currently unused, so lets omit them until
  they are needed. Probably when we start doing
  conformance testing.
- Also adds a bit of docs around this. More detailed
  docs will be added in future MRs.

Create canonical examples for parsing
and rendering audio and video in the
GitLab Flavored Markdown spec

Removes unnecessary normalization
(https://docs.gitlab.com/ee/development/gitlab_flavored_markdown/specification_guide/#normalization)
of the 07_01__gitlab_specific_markdown__footnotes__001
GLFM snapshot example, and instead uses the
GITLAB_TEST_FOOTNOTE_ID ENV var support which is already
used to generate the examples in
scripts/lib/glfm/update_example_snapshots.rb

- Add support for adding GitLab Flavored
  Markdown specification examples in H3
  headers.

MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/95302

Update snapshots generated from examples
of the GFM spec that can be interpreted
as frontmatter

Add new spec examples to describe
front matter parsing rules

Authored by ethan.reesor

Changelog: added

- Sets GITLAB_TEST_FOOTNOTE_ID to override random footnote
  ID generation in GLFM snapshot examples

MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/89953

- Add support for normalizing entries in
  GLFM static HTML snapshot examples, to replace
  variable values in actual HTML responses

- In glfm_canonical_examples.txt, remove placeholder sections
  and replace with actual section for footnotes, as well as
  some basic explanatory text

- Implement support and add documentation
  for example_status logic.
- See
  https://docs.gitlab.com/ee/development/gitlab_flavored_markdown/specification_guide/#glfm_example_statusyml

- Markdown example YML rendering
- Static HTML rendering via GLFM internal markdown helper
- Successfully rendering (with skip of failed examples)
  WYSIWYG HTML and Prosemirror JSON YML for all examples
  via new 'remark' Content Editor deserializer.

https://gitlab.com/gitlab-org/gitlab/-/issues/361241

- Add headers and anchors for individual input
  and output files.

- See related documentation added in
  https://gitlab.com/gitlab-org/gitlab/-/merge_requests/84220

MR: https://gitlab.com/gitlab-org/gitlab/-/issues/360212