Changes for cronjob related changes and additional scheduling options (#55365)

Co-authored-by: John Clement <70238417+jclement136@users.noreply.github.com>

Author: sachin-sandhu

content/code-security/dependabot/working-with-dependabot/dependabot-options-reference.md

@@ -482,18 +482,22 @@ Reviewers must have at least read access to the repository.
 | `interval` | **Required.** Defines the frequency for {% data variables.product.prodname_dependabot %}. |
 | `day` | Specify the day to run for a **weekly** interval. |
 | `time` | Specify the time to run. |
+| `cronjob` | Defines the cron expression if the interval type is `cron`. |
 | `timezone` | Specify the timezone of the `time` value.  |
 
 ### `interval`
 
-Supported values: `daily`, `weekly`, or `monthly`
+Supported values: `daily`, `weekly`, `monthly`, `quarterly`, `semiannually`, `yearly`, or `cron`
 
 Each package manager **must** define a schedule interval.
 
 * Use `daily` to run on every weekday, Monday to Friday.
 * Use `weekly` to run once a week, by default on Monday.
 * Use `monthly` to run on the first day of each month.
-
+* Use `quarterly` to run on the first day of each quarter (January, April, July, and October).
+* Use `semiannually` to run every six months, on the first day of January and July.
+* Use `yearly` to run on the first day of January.
+* Use `cron` for cron expression based scheduling option. See [`cronjob`](#cronjob).
 By default, {% data variables.product.prodname_dependabot %} randomly assigns a time to apply all the updates in the configuration file. You can use the `time` and `timezone` parameters to set a specific runtime for all intervals.
 
 ### `day`
@@ -508,6 +512,40 @@ Format: `hh:mm`
 
 Optionally, run all updates for a package manager at a specific time of day. By default, times are interpreted as UTC.
 
+### `cronjob`
+
+Supported values: Valid cron expression in cron format or natural expression.
+
+Examples : `0 9 * * *`, `every day at 5pm`
+
+cron format is defined as the following:
+* `*` The minute field.
+* `*` The hour field (in 24-hour time).
+* `*` The day of the month (matches any day of the month).
+* `*` The month (matches any month).
+* `*` The day of the week (matches any day of the week).
+
+`0 9 * * *` is equivalent to "every day at 9am". `every day at 5pm` is equivalent to `0 17 * * *`.
+
+> [!NOTE]
+> A `cronjob` type schedule is required to use a `cron` interval.
+
+```yaml copy
+
+# Basic `dependabot.yml` file for cronjob
+
+version: 2
+updates:
+  # Enable version updates for npm
+  - package-ecosystem: "npm"
+    # Look for `package.json` and `lock` files in the `root` directory
+    directory: "/"
+    # Check the npm registry for updates based on `cronjob` value
+    schedule:
+      interval: "cron"
+      cronjob: "0 9 * * *"
+```
+
 ### `timezone`
 
 Specify a time zone for the `time` value.