Add lint rule that headings must increment one level at a time

Also fixes instances in Markdown that broke the rule.

1 files changed, 6 insertions, 6 deletions

diff --git a/doc/development/changelog.md b/doc/development/changelog.md
index f13c447fef2..3ed586f07e9 100644
--- a/doc/development/changelog.md
+++ b/doc/development/changelog.md
@@ -144,7 +144,7 @@ If you're working on the GitLab EE repository, the entry will be added to
 | [`--type`](#--type-or--t)          | `-t`      | The category of the change, valid options are: `added`, `fixed`, `changed`, `deprecated`, `removed`, `security`, `performance`, `other` |
 | `--help`          | `-h`      | Print help message                                                                                                                      |
 
-##### `--amend`
+#### `--amend`
 
 You can pass the **`--amend`** argument to automatically stage the generated
 file and amend it to the previous commit.
@@ -166,7 +166,7 @@ author:
 type:
 ```
 
-##### `--force` or `-f`
+#### `--force` or `-f`
 
 Use **`--force`** or **`-f`** to overwrite an existing changelog entry if it
 already exists.
@@ -184,7 +184,7 @@ author:
 type:
 ```
 
-##### `--merge-request` or `-m`
+#### `--merge-request` or `-m`
 
 Use the **`--merge-request`** or **`-m`** argument to provide the
 `merge_request` value:
@@ -199,7 +199,7 @@ author:
 type:
 ```
 
-##### `--dry-run` or `-n`
+#### `--dry-run` or `-n`
 
 Use the **`--dry-run`** or **`-n`** argument to prevent actually writing or
 committing anything:
@@ -216,7 +216,7 @@ type:
 $ ls changelogs/unreleased/
 ```
 
-##### `--git-username` or `-u`
+#### `--git-username` or `-u`
 
 Use the **`--git-username`** or **`-u`** argument to automatically fill in the
 `author` value with your configured Git `user.name` value:
@@ -234,7 +234,7 @@ author: Jane Doe
 type:
 ```
 
-##### `--type` or `-t`
+#### `--type` or `-t`
 
 Use the **`--type`** or **`-t`** argument to provide the `type` value: