docs: reference canonical submission-hooks doc instead of duplicating (#533)

Replace the duplicated "Pre-GUI Submission Hooks" README section with a
concise "Submission Hooks" reference. DCC repos should point to the
canonical documentation in the AWS Deadline Cloud client library rather
than maintaining their own copy of the hooks.yaml format, field lists,
and caveats.

Keeps a short Cinema 4D-specific note (hooks sourced from
DEADLINE_HOOKS_DIR, enabled via settings.allow_environment_hooks, opened
from Extensions > AWS Deadline Cloud Submitter) and links the base doc
for the rest. Docs only.

Signed-off-by: Leon Li <2182521+leon-li-inspire@users.noreply.github.com>

Author: leon-li-inspire

README.md

@@ -13,7 +13,7 @@ For instructions on installing and using this integration, visit the [user guide
 [cmf-ubl]: https://docs.aws.amazon.com/deadline-cloud/latest/developerguide/cmf-ubl.html
 [deadline-cloud]: https://docs.aws.amazon.com/deadline-cloud/latest/userguide/what-is-deadline-cloud.html
 [deadline-cloud-client]: https://github.com/aws-deadline/deadline-cloud
-[submission-hooks]: https://github.com/aws-deadline/deadline-cloud#submission-hooks
+[submission-hooks]: https://github.com/aws-deadline/deadline-cloud/blob/mainline/docs/submission-hooks.md
 [openjd-template]: https://github.com/OpenJobDescription/openjd-specifications/wiki/2023-09-Template-Schemas
 [openjd-adaptor-runtime]: https://github.com/OpenJobDescription/openjd-adaptor-runtime-for-python
 [openjd-adaptor-runtime-lifecycle]: https://github.com/OpenJobDescription/openjd-adaptor-runtime-for-python/blob/release/README.md#adaptor-lifecycle
@@ -140,98 +140,23 @@ chmod +x ~/Desktop/Cinema4D.command
 
 To open Cinema 4D on Mac, click `Cinema4D.command` on your desktop. After you load a scene, click on `Extensions` > `AWS Deadline Cloud Submitter` to view the submitter.
 
-## Pre-GUI Submission Hooks
-
-The Cinema 4D submitter supports **pre-GUI hooks** — studio-provided scripts that run *before* the
-`Submit to AWS Deadline Cloud` dialog opens, so you can pre-populate the job name, description, and
-shared job properties (priority, maximum failed tasks, maximum retries, Conda packages, etc.). This
-is useful for enforcing studio defaults or pulling values from a pipeline / asset-management system
-before an artist sees the dialog.
-
-Pre-GUI hooks are provided by the [AWS Deadline Cloud client library][deadline-cloud-client] and are
-shared across DCC submitters. For Cinema 4D, hooks are sourced only from the directory named by the
-`DEADLINE_HOOKS_DIR` environment variable — the Cinema 4D submitter has no on-disk job bundle at
-pre-GUI time, so bundle-sourced hooks do not apply. They complement the `preSubmission` /
-`postSubmission` hooks that run at submit time (see [Submission Hooks][submission-hooks]).
-
-Pre-GUI hook support requires the `deadline` client library that ships with
-`deadline-cloud-for-cinema-4d[gui]` (`deadline[gui] >= 0.60.4`), which is installed for you when you
-install the submitter as described above.
-
-### Enabling pre-GUI hooks
-
-1. Allow environment-sourced hooks in your Deadline Cloud configuration (off by default):
-   ```
-   deadline config set settings.allow_environment_hooks true
-   ```
-2. Point `DEADLINE_HOOKS_DIR` at a directory that holds your hook script(s) and a `hooks.yaml`.
-
-   On Windows (`cmd`):
-   ```cmd
-   setx DEADLINE_HOOKS_DIR "C:\deadline-hooks"
-   ```
-   On macOS/Linux:
-   ```
-   export DEADLINE_HOOKS_DIR="$HOME/deadline-hooks"
-   ```
-   Restart Cinema 4D (or log out/in on Windows) so the running Cinema 4D process picks up the
-   environment variable before you open the submitter.
-3. Create `hooks.yaml` in that directory with a `preGUI` entry:
-   ```yaml
-   preGUI:
-     - command: C:/Program Files/Python311/python.exe
-       args:
-         - C:/deadline-hooks/pregui_hook.py
-       timeout: 60
-   ```
-   **Tip:** point `command` at a clean, standalone Python interpreter rather than Cinema 4D's
-   bundled interpreter — a bundled interpreter can print a startup banner to stdout that corrupts
-   the hook's JSON output.
-
-### Writing a pre-GUI hook
-
-A pre-GUI hook receives the current submission metadata as JSON on **stdin** and returns the fields
-it wants to override as JSON on **stdout**. Recognized keys are `name`, `description`, and
-`parameters` (a map of parameter name → value). `deadline:`-prefixed keys map to shared job
-properties — for example `deadline:priority`, `deadline:maxFailedTasksCount`, and
-`deadline:maxRetriesPerTask` — and `CondaPackages` overrides the Conda packages queue parameter.
-
-```python
-# pregui_hook.py
-import json, sys
-
-metadata = json.load(sys.stdin)  # jobName, submitterName ("cinema4d"), parameters, farmId, queueId, ...
-
-print(json.dumps({
-    "name": "MyStudio Shot 010",
-    "description": "Submitted via MyStudio pipeline",
-    "parameters": {
-        "deadline:priority": 75,
-        "deadline:maxFailedTasksCount": 5,
-    },
-}))
-```
-
-When the submitter opens, its **Name** / **Description** and **Priority** / **Maximum failed tasks
-count** / **Maximum retries per task** fields on the shared job settings tab (plus any other
-returned shared parameters, such as `CondaPackages`) are pre-populated from the hook's output.
+## Submission Hooks
 
-> **Note:** pre-GUI hooks set the shared job properties above; they do **not** set the Cinema
-> 4D-specific render options (take selection, frame range, output path, multi-pass path, tile
-> rendering, chunk size, error checking, detailed logging, etc.). Those are initialized from the
-> Cinema 4D scene's render settings and the per-scene sticky settings, and remain editable in the
-> submitter UI.
+The Cinema 4D submitter supports Deadline Cloud **submission hooks** — studio-provided scripts that
+run at submission time to customize a job. Pre-GUI hooks run *before* the `Extensions` > `AWS
+Deadline Cloud Submitter` dialog opens (to pre-populate fields such as the job name, description,
+and priority); pre-submission and post-submission hooks run around job creation.
 
-### Confirmation prompt
-
-Before running any hooks, the submitter shows a **Job Submission Confirmation** dialog listing the
-hook scripts that will execute. Click **Yes** to run them, or **No** to cancel — clicking **No**
-aborts opening the submitter cleanly (no error). To skip the prompt on non-interactive or
-studio-locked workstations, enable auto-accept:
+Hooks are sourced from the directory named by the `DEADLINE_HOOKS_DIR` environment variable, which
+must first be enabled in your Deadline Cloud configuration:
 ```
-deadline config set settings.auto_accept true
+deadline config set settings.allow_environment_hooks true
 ```
 
+For the `hooks.yaml` format, the data passed to hooks, the fields you can override, and the
+confirmation-prompt and failure behavior, see the canonical documentation in the AWS Deadline Cloud
+client library: [Submission Hooks][submission-hooks].
+
 ## Adaptor
 
 Jobs created by the Cinema 4D submitter require the adaptor to be installed on your worker hosts.